UNIVERSITI PUTRA MALAYSIA

Transcription

1 UNIVERSITI PUTRA MALAYSIA SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF MALAY FOLK INSTRUMENTS ANG YAW FENG FEM

2 SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF MALAY FOLK INSTRUMENTS By ANGYAWFENG Thesis Submitted in Fulfilment of the Requirement for the Degree of Master of Science in the Faculty of Human Ecology Universiti Putra Malaysia April 2001

3 Abstract of thesis presented to the Senate ofuniversiti Putra Malaysia in fufilment of the requirement for the degree of Master of Science. SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF MALAY FOLK INSTRUMENTS By ANG YAW FENG April 2001 Chairman: Minni Ang Kim Huai, Ph.D. Faculty: Human Ecology A random survey of commercial synthesisers available shows that sampled sounds of Malay folk instruments such as the rebab, seruling and others are lacking in both fonns of software or hardware, in sharp contrast to Western classical instrument sounds where similar materials are in abundance. This study attempts to create original sound banks of selected Malay folk instruments in two fonnats, SoundFonts (SFs) and the Downloadable Sounds (DLS) fonnats by application of the sampling synthesis method and analysis of the waveforms of selected instruments. The recorded sound samples of individual selected Malay folk instruments are organised 11

4 and sequentially edited according to established procedures of trimming, normalisation, conversion and pitch shifting. The identification of the ADSR envelope and frequency components of specific instruments' waveform is also carried out. Finally, the creation of SoundFonts and DLS instruments is undertaken. As a result of this study, the following have been achieved: a) The production of high quality and realistic soft sound banks of selected Malay folk instruments in the SoundFonts (SFs) and the Downloadable Sounds (DLS) formats. b) A detailed analysis of waveforms and frequency components produced by selected Malay folk instruments. It is hoped that these sound banks would be useful as a source of musical tones, applicable for playback of MIDI sequences orchestrated utilising Malay folk instruments, for use by composers as well as commercial products such as synthesisers, samplers and keyboards. iii

5 Abstrak tesis yang dikernukakan kepada Senat Universiti Putra Malaysia sebagai rnernenuhi keperluan untuk ijazah Master Sains. TEKNIK SINTESIS PERSAMPELAN UNTUK PENJANAAN SECARA DIGITAL NADA ALAT MUZIK TRADISI MELAYU Oleh ANG YAW FENG April 2001 Pengerusi: Minni Ang Kim Huai, Ph.D. FakuIti: Ekologi Manusia Satu kajian sernasa secara rawak ke atas sintesiser kornersial menunjukkan ketiadaan sarnpel bunyi alat muzik tradisi Melayu seperti rebab, seruling dan lainlain, rnahupun dalam bentuk perisian atau perkakasan. Ini arnat berbeza dengan sarnpel bunyi alat rnuzik Barat yang rnudah diperolehi dalarn konteks perisian dan perkakasan yang sarna. Kajian ini bertujuan mencipta arkib digital alat muzik tradisi Melayu dalam dua format, SoundFonts (SFs) dan Downloadable Sounds (DLS), secara aplikasi teknik sintesis persarnpelan termasuk analisis gelombang. Bunyi alat rnuzik tradisi Melayu yang dirakarnkan disunting, diikuti dengan prosedur iv

6 pemerosesan berikut: 'trimming', 'normalisation', 'conversion' dan perubahan pic. Langkah ini diikuti dengan prosedur analisis gelombang yang merangkumi pengenalpastian komponen frekuensi yang hadir di dalam spektrum alat muzik tradisi Melayu yang terpilih serta sampul ADSR untuk setiap gelombang. Proses ini berakhiri dengan penciptaan SoundFonts and alat-alat DLS. Kajian ini telah berjaya mencapai: a) Arkib digital nada alat muzik tradisi Melayu dalam format SFs serta DLS; b) Analisis gelombang serta komponen frekuensi yang wujud di dalam spektrum alat muzik tradisi Melayu. Hasil projek ini boleh digunakan oleh pencipta muzik serta produk komersil seperti sintesiser, sampler dan alat kibod. v

7 ACKNOWLEDGEMENTS I would like to register my gratitude to my mentor and supervisor, Dr. Minni Ang Kim Huai whose advice, encouragement, guidance, and supervision made this study possible. I am also deeply indebted to her for painstakingly going through the manuscript. Next, I would like to extend my heartfelt thanks to my second supervisor, Mr Paul Isitt for his invaluable feedback and suggestions, especially regarding the method in creating SoundFonts banks using the Vienna software. My special thanks to my third supervisor, Mr. Chan Cheong Jan for his ideas and input throughout this study. I would like to thank the National Arts Academy or Akademi Seni Kebangsaan (ASK), for allowing me to record all my samples there. Also, the most noted player of the ASK, Encik Mohd. Kamarulbahri Hussin for his assistance in spending much of his precious time to play all the chosen Malay folk instruments. I am also grateful to Encik Hamzah Awang Amat, a very skilful player with more than 10 years of experience in making Malay traditional instruments in Malaysia, for preparing the various instruments used in this research project. My thanks are also accorded to Mr. Rick Craig Shriver for imparting to me his knowledge of recording techniques. I am also indebted to the Universiti Putra Malaysia Graduate School for the Pasca Siswazah Award scheme, which supported this study throughout the two years duration. Last but not least, I would like to extend my gratitude to all my research colleagues, Bee Suan, Julie, Yoke Fun and Ee Lyn, for their understanding and co-operation, and my parents for their encouragement, support and love. VI

8 I certify that an ExammatIOn CommIttee met on 29 th April 2001 to conduct the final exammation of Ang Yaw Feng on her Master of SCIence thesls entltled "Samphng SyntheSIS TechnIque ApplIed for the DIgItal GeneratIOn Of MUSIcal Tones of Malay Folk Instruments" m accordance WIth Umversltl Putra MalaYSIa (HIgher Degree) Act 1980 and UmversltI Putra MalaYSIa (HIgher Degree) RegulatIOn The CommIttee recommends that the candidate be awarded the relevant degree ExammatIOn CommIttee are as follows Members of the Martha Lee Jm AI, M A Faculty of Human Ecology UmversltI Putra MalaYSIa (ChaIrman) Mmm Ang KIm HUaI, Ph D Faculty of Human Ecology Umversitl Putra MalaYSIa (Member) Paul ISltt, MMus Faculty of Human Ecology Umverslty Putra MalaYSIa (Member) Chan Cheong Jan, M Ed Mus Faculty of Human Ecology Umverslty Putra MalaYSIa (Member) AINI IDERIS, Ph D, Professor / Dean of Graduate School, Umvelsltl Putra MalaYSIa Date 3 0 MAY 2001, VII

9 This Thesis was submitted to the Senate of Universiti Putra Malaysia has been accepted as fulfillment of the requirements for the degree of Master of Science. AINI IDERIS, Ph. D, Professor / Dean of Graduate School, Universiti Putra Malaysia. Date: viii

10 DECLARATION FORM I hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions. Candidate. ANG YAW FENG Date: 1ft /s I 0 f IX

11 TABLE OF CONTENTS Page ABSTRACT...,...'".,...,... '"..,...,."..., ABSTRAK... iv ACKNOWLEDGEMENTS... APPROV AL SHEETS...,..., DECLARATION FORM... LIST OF TABLES LIST OF FIGURES... '".,...,... LIST OF ABBREVIATIONS... VI Vll IX XlI XIV XVI CHAPTER I INTRODUCTION.... Statement of the Problem.... Objective of the Study Significance of the Study Design of the Study Organisation of the Thesis... 5 n LITERATURE REVIEW Preservation of Musical Instruments Culture Theory of Sampling Synthesis The Process of Digital Sampling Critical Factors of Creating Good Samples Sampling Synthesis Research...,.. 18 Soft Sound Bank Formats..., SoundFonts (SFs) Downloadable Sound (DLS) Conclusion III METHODOLOGy...'"..., Sample Recording Prerequisites Recording Set Up...'" Recording Section Sample Organisation...'"... '"...,...,... Sound Editing TnmmIng Normalisation Conversion x

12 Pitch shifting...'" '"..., Wavefonn Analysis...'"..., '" ADSR Envelope Identification Frequency Components Identification..."..." '" SoundFonts and DLS Instrument Creation SoundFonts Creation...'".., DLS Instrument Creation Conclusion...'" IV RESULTS AND DISCUSSION The Recording of selected Malay Folk Instruments The ADSR Envelope Analysis The Frequency Analysis SoundFont banks and DLS instrument Creation Discussion... '".., Hard disk space and RAM optimisation Realism of tone production Accuracy of intonation and error-correction methods Comparison between SoundFonts and DLS Conclusion...,...,."...'"..,."..,...,..., V CONCLUSION AND SUGGESTIONS FOR FURTHER STUDy Summary ofthe Thesis Conclusion...'" Suggestion for Further Study BIBLIOGRAPHy APPENDICES A List of Malay Folk Instruments Wave Files '" B List of Malay Folk Instruments Image Files C Wavefonn Envelope of the Malay Folk Instruments..., D Tables of Frequency Analysis Results E SoundFont Bank and DLS Instrument Creation Results...'" F The Frequency Value and Midi Number of Each Note..." 160 G General Infonnation on the Malay Folk Instruments H Definitions I Publication Arising from this Research Project BIODATA OF AUTHOR Xl

13 LIST OF TABLES Table Page 1 The Sample Rates versus the Nyquist Frequency The Number of Bits versus the SNR The Key Group Assignment of Different Malay Folk Instruments The Duration of Each ADSR Portion of the Malay Folk Instruments ADSR Waveforms Types List of Stereo Wave Files List of Mono Wave Files List of Photographic Images Frequency Analysis Result of Gambus [C3} Frequency Analysis Result of Rebab [C4} Frequency Analysis Result of Seruling [C5} Frequency Analysis Result of Serunai [C5} Frequency Analysis Result of Angklung Anak Frequency Analysis Result of Angklung Ibu Frequency Analysis Result of Gendang Anak (Cak) Frequency Analysis Result of Gendang Anak (Ting) Frequency Analysis Result of Gendang Anak (Tak) Frequency Analysis Result of Gendang Ibu (Pak) Frequency Analysis Result of Gendang Ibu (Duh) Frequency Analysis Result of Gendang Ibu (Tak) Frequency Analysis Result of Gedombak Anak (Cak) Frequency Analysis Result of Gedombak Anak (Doh) Frequency Analysis Result of Gedombak Anak (Ting) Frequency Analysis Result of Gedombak Ibu (Cak) l38 25 Frequency Analysis Result of Gedombak Ibu (Doh) Frequency Analysis Result of Gedombak Ibu (Ting) l30 27 Frequency Analysis Result of Geduk Anak Frequency Analysis Result of Geduk Ibu Frequency Analysis Result of Kompang (Cak) Frequency Analysis Result of Kompang (Doh) Frequency Analysis Result of Kompang (Tak) " Frequency Analysis Result of Rebana (Doh) Frequency Analysis Result of Rebana (Gong) l35 34 Frequency Analysis Result of Rebana (Pak) Frequency Analysis Result of Rebana (Tak) Frequency Analysis Result of Canang Anak Frequency Analysis Result of Canang Ibu... Frequency Analysis Result of Kesi (Cap) Frequency Analysis Result of Kesi (Ong) xii

14 (Continued) 40 Frequency Analysis Result of Gong Anak Frequency Analysis Result of Gong Ibu Frequency Analysis Result of Gong Anak (Muted) Frequency Analysis Result of Gong Ibu (Muted) Patches Created for the SFs of Individual Malay Instrument Patches Created for the DLS of Individual Malay Instrument Patches Created for the "Malay Percussion" SFs Patches Created for the "Malay Percussion" DLS Patches Created for the "Malay" SFs Patches Created for the "Malay" DLS Patches Created for the "Malay Drums 1" SFs Patches Created for the "Malay Drums 1" DLS Parameter Details for the "Malay" SFs Parameter Details for the "Malay" DLS Parameter Details for the "Malay Drums 1" and "Malay Drums 2" SFs Parameter Details for the "Malay Drums 1" and "Malay Drums 2" DLS Parameter Details for the Gedombak of "Malay Drums 2" SFs and DLS Parameter Details for other Malay Drums of "Malay Drums 2" SFs and DLS Parameter Details of "Malay" SFs (High Quality) Parameter Details of "Malay" DLS. (High Quality) List of Frequency Value and Midi Number for Each Note xiii

15 LIST OF FIGURES Figure Page 1 Time-Varying Voltage Sampled Periodically An Overview of a Complete Sampling System The Sample Rate and Sample Resolution of Portion Waveform The Relationship between Preset, Instrument and Sample A Diagram of the DLS Architecture The Digital Audio Engine...,..,. '" A Diagram of the Melodic Instrument Architecture A Diagram of the Drum Kit Architecture The Position ofx-y Coincident Miking Trimming a Sound Sample Waveform Normalisation of a Sound Sample Waveform The Pitch Bender Window An ADSR Amplitude Envelope " Six Added Harmonics Derived from a Fundamental Frequency and the Next Five Harmonics The Spectrum of a Tone The SoundFont Tree View , Keyboard Range List Box for Vienna SFs Editor Root-Key Number Setting Full View of the Rebab Waveform in Global Loop Marking Dialog Box Incorrect Loop Point Results in Aliasing Zero Crossing Technique Used in Defining Global Loop Two Additional Check Boxes in Layout of the Local Dialog Box for Loop Marking , The Instrument Setting for a DLS Instrument , The Region Setting for a DLS Instrument Diagrammatic Representation of the Methodology Three Types of ADSR Waveforms Difference in Waveform Shape between Angklung and Seruling, Serunai or Rebab Waveform Envelope of the Angklung Anak Waveform Envelope of the Angklung Ibu Waveform Envelope of the Canang Anak Waveform Envelope of the Canang Ibu Waveform Envelope of the Gambus (Finger) [C3] Waveform Envelope of the Gambus (Plectrum) [C3] Waveform Envelope of the Gedombak Anak (Cak) Waveform Envelope of the Gedombak Anak (Dong)... '" xiv

16 ( Continued) 36 Wavefonn Envelope of the Gedombak Anak (Ting)..., Wavefonn Envelope of the Gedombak Ibu (Cak) Wavefonn Envelope of the Gedombak Ibu (Dong) Wavefonn Envelope of the Gedombak Ibu (Ting) Wavefonn Envelope of the Geduk Anak Waveform Envelope of the Geduk Ibu Waveform Envelope of the Gendang Anak (Cak) Waveform Envelope of the Gendang Anak (Ting) , Waveform Envelope of the Gendang Anak (Tak) Wavefonn Envelope of the Gendang Ibu (Pak)..., Wavefonn Envelope of the Gendang Ibu (Duh) Wavefonn Envelope ofthe Gendang Ibu (Tak) Wavefonn Envelope of the Gong Anak (Muted) Wavefonn Envelope of the Gong Anak...,..., Waveform Envelope of the Gong Ibu (Muted) Wavefonn Envelope of the Gong Ibu III 52 Wavefonn Envelope of the Kesi (Cap) Wavefonn Envelope of the Kesi (Cing) Wavefonn Envelope of the Kompang (Cak} Wavefonn Envelope of the Kompang (Doh} Wavefonn Envelope of the Kompang (Tak) Waveform Envelope of the Rebab [C4] Waveform Envelope of the Rebana (Doh) Waveform Envelope of the Rebana (Gong) Wavefonn Envelope of the Rebana (Pak) '".., Wavefonn Envelope of the Rebana (Tak} Wavefonn Envelope of the Seruling [C5] Wavefonn Envelope of the Serunai [C5]... '" xv

17 LIST OF ABBREVIATIONS 12-ET ADC ADR ADSR AR CD-ROM DAT DAW DB DCA DFS DLS DVD Egs FM GM KHz LD LFO LSB MB Mbps MD MDM MIDI MMA MSB PC PCM RIFF SNR STFT 12-tone equal-tempered AJD converter or analogue to digital converter attack decay release attack, decay, sustain, release attack release compact disc read only memory digital audio tape digital audio workstations decibel digitally controlled amplifier digital full scale downloadable sounds specification. digital video disc or digital versatile disc envelope generators frequency modulation general MIDI kilohertz! thousands of cycles per second laser disc low frequency oscillator least significant byte megabytes megabits per second mini disc multi track digital multi-tracks musical instrument digital interface MIDI Manufacturer's Association most significant byte personal computer pulse code modulation resource interchange file format signal-to-noise ratio short-time Fourier transform xvi

18 CHAPTER ONE INTRODUCTION Sampling is a process where sound [an analogue signal] is recorded digitally. When sound is recorded into a sampler, it turns the audio waveform into a series of binary numbers or bits [Os and Is], that can easily be shuffled around and reassembled. This process is achieved with an electronic circuit called an analogueto-digital converter (AID converter or ADC for short). In contrast, analogue recording is based on the voltage recorded as patterns of magnetisation in the oxide particles of the recording tape. (Snyder, 1999). For instance, individual musical instrument tones once recorded, can then be played back on a keyboard. These individual tones, commonly referred to as "samples", could be stored on a CD ROM (Compact Disc-Read Only Memory) or hard disk, but are read in RAM memory for speedy access. The term sampling is derived from established notions of digital samples and sampling rates. "Sampling Rates" in tum, refers to the number of samples that are taken of an analogue signal per second. The more regularly samples are taken, the better the result will be when the sample is played back (Roads, 1996). This is due to the mechanics of recording devices capable of capturing tiny variations in the sound waves more accurately. As a result, this produces higher fidelity recordings with less distortions (Rubin, 1995).

19 2 Sampling thus has an edge over multiple wave cycling, in that it applies a longer wavetable containing thousands of individual cycles - several seconds of prerecorded sounds, permitting the use of pointers within a sample to define internal looping. It creates samples from live and pre-recorded materials. Recorded sound can be stored in disks, or in the internal memory (Roads, 1996; Dodge & lerse, 1997). The sample later can be spliced, copied, reversed, enveloped, cross-faded, looped, sped up or manipulated in any combination of the above in order to change the duration, pitch and timbre. Effects such as reverberation or flanging can also be introduced in the wave-shaping process. As a result, it is usually used to create sonorities and effects that would normally not be possible to achieve acoustically. (Moore, 1996; Miranda, 1998). In effect, sampling synthesis permits the production of rich, natural, and time-varying sounds useful for composition, live performance and sound effects purposes. It has minimal flexibility since only few transformations are possible at this level. (De Poli, 1996). The input signal is always the same, as it is recorded. The input signal is a recorded sound resulting in the absence of the control over life-like qualities of sounds that help enhance the perception of music. Today, there are many different formats or arrangements of data used for describing samples. Two of the most common are the SoundFonts (SFs) 2.0 format patented by Creative Technology Limited, and the Downloaded Sounds (DLS) format standardized by the MIDI Manufacturers Association (MMA). (Scheirer, 1999). The primary objective of this study is to obtain original banks of sound samples of selected Malay folk instruments in the form of these two formats. All the sound

20 3 samples can either be uploaded onto the internet or recorded into a CD-ROM for further usage, as well as loaded into commercial synthesisers. Malay folk instruments that have been chosen for this study are categorised according to instrument families as follows: a) String instruments or chordophones': gambus and rebab [Malay violin]; b) Wind instruments or aerophones2: seruling [flute] and serunai; c) Percussion instruments: i) Membranophones3: gedombak, geduk, gendang [bigger drums], kompang and rebana and ii) Idiophones4: angklung, canang, kesi, and tetawak or gong. Statement of the Problem A random survey of commercial synthesisers available shows that sampled sounds of Malay folk instruments such as the rebab, seruling and others have yet to be found in any of these products whether in the form of software or hardware. On the other hand, Western classical instruments sounds and other variety of other sounds have long been sampled in those products. Also, no study has been carried out on analysing the waveform of the sound produced by Malay folk instruments to date. I Chordophones refers to instruments using a stretched string as sound generator. 2 Aerophones are instruments producesing sound with a column of air. JMembranophones refers to instruments with stretched skin or other membrane for sound generation. 4Idiophones refers to instruments made up of material with self-generating sounds.

21 4 Objective of the Study The primary objective of this study aims at obtaining a high quality sound bank of Malay folk instruments in the SoundFonts (SFs) formats and the Downloadable Sounds (DLS) by applying the sampling synthesis method, besides obtaining an analysis of waveforms produced by each of the Malay folk instruments. Significance of the Study This study is primarily targeted towards the musician in the field of music technology and manufacturers of musical instruments. By producing the sampled sound of Malay folk instruments, it is hoped that composers will be able to utilise these sound fonts, with Compact Disc (CD) quality sound of MIDI (Musical Instrument Digital Interface) playback for their own compositions, particularly for those who attempt to compose music using Malay folk instruments. In doing so, they will be able to hear the immediate effects of the Malay folk instruments when they use these instruments in their compositions, whilst manufacturers of commercial musical instruments such as synthesisers, samplers and keyboards could hopefully incorporate these realistic representations of eastern instruments into their products in future.

22 5 Design of the Study This study is divided into five mam sections. The sections are, accordingly: sample recording, sample organisation, sound editing, wavefonn analysis succeeeded by SoundFonts and DLS intruments creation. Initally, the sound samples of the selected Malay folk instruments are recorded onto Digital Audio Tape (DAT). After that, the sound samples are transferred to computer hard disk, organised systematically into different catogories and stored using descriptive file names. The wave files are then edited with the trimming, nonnalisation, conversion and pitch shifting processes done at this stage 5. Later, the wavefonn of each different Malay folks instruments' sound sample is analysed from two points of view: the ADSR envelope and the frequency components. Finally, the SoundFonts and DLS instruments are created using the software Vienna 2.3 and Direct Music Producer respectively. Organisation of the Thesis This thesis is organised into five chapters. Chapter two deals with the research literature review, commencing with a discussion on the preservation of Malay folk instruments culture, followed by an explanation of the theory of sampling synthesis, the digital sampling process and critical factors in producing a good sample. This is 5 These terms will be explained in Chapter Three, when the methodology is described in detail

23 6 followed by a review of sampling synthesis from a historical and developmental perspective, as well as current research trends. The chapter concludes with a discussion on the two soft sound bank formats used in this research, SoundFonts (SFs) and Downloadable Sounds (DLS). Chapter Three deals in detail with the methodology of the whole study. This chapter contains five main sections: sample recording methodology, sample organisation, sound editing methodology, waveform analysis methodology and finally, SoundFonts and DLS instruments creation methodology. The fourth chapter contains results and discussions, including results of the waveform analysis performed on the various samples. The SoundFonts and DLS instruments created through this research are appended to this thesis in the form of a CD-ROM. Background information on each of the Malay folk instruments selected is presented as an appendix to the main text. Conclusions of the research are presented in the last chapter, along with suggestions for further studies. The following chapter presents the review of related literature.

24 CHAPTER TWO LITERATURE REVIEW This chapter presents the literature review related to this study. It begins with a discussion on the preservation of Musical instruments culture, followed by the theory of sampling synthesis. This section is further subdivided into the digital sampling process and critical factors involved in creating good samples. After that, sampling synthesis research is considered. Finally, the chapter ends with a discussion on SoundFonts (SFs) and Downloadable Sounds (DLS). Preservation of Musical Instruments Culture From the end of 19 th century, efforts have been made by ethnomusicologists to preserve culture through assembling primary sources from target fieldwork in various ways: observation in fieldwork, music recordings and interviews, photographs, film and video taping. In this regard, documentary recording has been vital in preserving traditional music. Ethnomusicologists have used sound recording as an integral part of their scholarly texts, instead of being limited to the written word, such as for musicology work. Recording technology has provided the ethnomusicologist and musicologist the means to preserve, duplicate and reshape raw data using the latest technology. In the early days of culture preservation, the recording technology employed was mainly analogue. Magnetic tape, open-reel, videotape and cassette were utilised in order to capture the sound of traditional instruments (MaIm, 1992; Myers, 1990). The cassette 7

25 8 restricted signal-to-noise ratio (SNR) (Refer page 17) and limited frequency response, both resulting from the narrow track width and slow tape speed, and these cumulate in noisy recordings with background hiss. In retrospect, it is little wonder that digital recording has dominated the recording scene since the 1990s. One major advantage of digital recording is generally providing high quality sound recording. Besides, recorded signals do not degenerate with repeated playing. Furthermore, it is possible to generate copies from the original with equal fidelity to the original. The emergence of attainable standards in digital recording overcomes major problems prevalent in the days of analogue recording, such as tape noise and distortion. In this respect, a vast majority of digital recording systems are capable of detecting and eliminating interfering signals. Digital techniques also offer wide possibilities for the ethnomusicologist, who can apply computerised and synthesised digital recordings in their research. For instance, Simha Arom adapted a Yamaha synthesiser to simulate a traditional xylophone, recording the results on a Macintosh SE/30 computer. (Myers, 1992). Also, musicians managed to correct the tunings to reflect authentic African scales by utilising the computer (Myers, 1992). The most frequently used media for digital recording use the PCM (Pulse Code Modulation) system, including computer, Digital Audio Tape (DAT), compact disc (CD), Mini Disc (MD) and digital videodisc (DVD). (Refer page 12). According to Helen Myers (1992), among the DAT tape, videotape and the compact disc, the latter is said to be the most stable and likely to be the most permanent. In terms of