Contents

CONTENTS
Contents in detail
Introduction

The Operating System
About this book
Programs tape
Thanks and acknowledgments

CHAPTER 1 What is Sound?

The nature of sound
Looking at sound waves

Program notes

The sound of the BBC micro
Pitch: high and low notes
Volume
Duration: the length of a note
Motility: speed and accuracy

Program notes

Timbre: the quality of sound

CHAPTER 2 What is Music?

The language of music
The pitch of a note
Scales
Minor scales
Enharmonics
Accidentals
The length of a note
Beats in the bar
Triplets, ties, slurs and staccato
Harmony and chords

CHAPTER 3 The BBC Micro and Sound and Music

Pitch
Fitting the notes to the music
Volume and duration
Improving the sound output
Adding an external speaker
Another solution
Further improvements and considerations
Talking music
The numbers method
The other methods
Note to Number Conversion Program

Program notes

The lowest A#

CHAPTER 4 The SOUND Command

Channel and its extensions
Hold

Program notes

Synchronization
Flush

Program notes

Amplitude
Pitch
Duration
Out of range values

CHAPTER 5 The ENVELOPE Command

The complete ENVELOPE command
ADSR: the amplitude envelope
The attack phase
The decay phase
The sustain phase
The release phase
The complete ADSR envelope: putting them all together
ADSR and the ENVELOPE command
How to use the program

Program notes

The volume range: hardware and software differences
A detailed look at the amplitude commands
Using the program and further suggestions
The pitch envelope
PI and PN: the pitch change and the number of steps
The Pitch Graph Generator program
Using the program

Program notes

Apparent peculiarities of the pitch envelope
The value of T and bit 7
Experimenting with the programs
Instrument characteristics
Producing other waveforms

CHAPTER 6 Musical Miscellanea

Vibrato and tremolo: pitch and amplitude modulation
Comparing envelopes

Program notes

Using the program
Producing tremolo effects

Trills: a special kind of vibrato
ECHO ECHo ECho Echo echo and reverberationnnn
Commercial echo units
Producing echoes on the BBC micro
Pseudo echo
Using the pitch envelope to play tunes
Chorus, phasing, flanging and other spatial effects
Delay effects on the BBC micro
Beat frequencies: the weaving in and out
The ring modulator: producing bells and other ringing noises
The frequencies produced by the sound chip

The out of tune chip

Bells and the BBC micro

CHAPTER 7 Zaps and Zings and Other Things

White noise

Simple sound effects
The Machine Gun
The Ricochet
The Cymbal or Anvil
The Creature
The Mad Factory
Space Ship Taking Off

Exploring the sound channel
Sound Effects Generator program


How to use the program
Program notes

Suggestions and modifications
Using channel 0 to produce otherwise unobtainable low notes
Use of the lower octave
Designing a rhythm unit

Program notes

The CAPS LOCK and SHIFT LOCK lights and the ADVAL function
Using sound effects in utility programs
Soundscapes: a total sound effects program

Program notes

Further experiments in soundscapes

CHAPTER 8 Playing the BBC Micro

Using the BBC micro as a musical keyboard

Monophonic and polyphonic instruments
The BBC as a monophonic keyboard

Program notes

Keyboard display program
Alternative methods of note production

Program notes

How the program works and making modifications
Further additions to the musical keyboard: a bass sequencer

Program notes

Altering the bass riff
Developing the sequencer

CHAPTER 9 Making Micro Music

Playing two- or three-part tunes
Selecting the notes and octave range

Program notes

The tracking method
The negative ADVAL method

Program notes

Modifications, alterations and suggestions
Debugging the data
Saving the tune

Program notes

Experimenting with the program
More tunes to play

CHAPTER 10 Computer Compositions

The human compositional process: algorithms and heuristics
Aspects of a composition

Program notes

Experimenting with the program

Program notes

Note analysis in composition

Program notes

Experimenting with the program
A total tune analysis program

CHAPTER 11 More Programs that Compose

The harmonic structure of popular songs
Producing acceptable results
Random harmonic compositions
Instant Mozart
A three-part computer composition

Program notes

Calculating the duration values
Experimenting with the program
Using chords as a compositional base


Program notes

Experimenting with the program
Adding rhythmic variations
Further extensions and modifications
Applying further control to random note selections
Improving the melody
Bass notes
Designing and developing programs
The Amazing One Line Wonder Composer program
Sing-a-long-a-matic

CHAPTER 12 Harmony and Transposition

Harmonising a tune
A melody with chord symbols: what to put in
Working from a piano copy: what to leave out
Adding harmony to a melody line
Transposition
Instant computer transposition
Why transpose?
Calculating a transposition
The computer as a transposition aid

Program notes

Using the program
Accidentals
Transposing chords
Modifying the program

CHAPTER 13 The All-singing, All-dancing BBC Micro

Background music from BASIC
Cartoons
Sound and animation synchronization

Program notes

Hercules


Program notes

Further experiments in animation
Computer art
Tomorrow's BBC micro

APPENDIX 1 The Hardware and the Software

Interrupts

APPENDIX 2 Entering, Protecting and Working with the Programs

Using a cassette recorder
Verify command
Entering programs
Merging programs
Re-setting the random number generator

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