                         Synsounds

           Tim Closs provides a useful facility
              on a machine not noted for its
              sound potential - the Spectrum.

This program converts the 48K Sinclair ZX Spectrum into a
versatile electronic keyboard. Up to 100 different sound
effects can be synthesised by the user, any 10 of which can
be accessed instantly while playing a piece of music. In
addition, seven riffs can be stored in the memory and
incorporated into the performance at the touch of a key.

 Facilities on a main menu

All the facilities offered are obtainable from a main menu
displayed at the start of the program:
# Play.
# Synthesise sound effects.
# Assign sound effects.
# Compose riffs.
  Play: When this option is selected the screen is cleared
and the computer keyboard is arranged as in figure 1. [This
is the file Synsounds.png, which should be available from
the same place where you got this text.] The labeled keys
in the middle two rows are set out like a piano and can be
played in a similar manner. However, three octaves are
available, since pressing Octave Down will lower all notes
by one octave and Octave Up will raise them. Hours of fun
can be had from this basic electronic keyboard even if your
musical talent is strictly limited. But there's much more
to come.
  Synthesise sound effects: The essence of a syntheser is
to alter the kind of sound produced without altering the
musical pitch of the notes themselves. On the Spectrum this
can be achieved by causing a rapid change of frequency as
the note is played: the particular "frequency waveform"
governs the character of the sound emitted. In this program
the used is able to invent as many as 100 unique frequency
waveforms as follows.
  On choosing menu option 2 you are first required to enter
the number of the sound effect you are about to synthesise.
This should be within the range 0-99. Having done this, two
axes will appear on the screen - see figure 2. [This can be
found at the end of this document.] The horizontal time
axis covers the duration of the note, and is divided into
16 sectors, while the vertical axis represents frequency.

 Beep returns you to menu

To draw out your frequency waveform, keys 6 and 7 are used
to move a bar up and down each sector, and key 0 enters the
desired level when it is reached. After levels in all 16
sectors have been defined in this way, a short beep returns
you to the main menu.
  Some examples of waveforms are depicted in figure 3, but
you will obviously want to experiment with your own ideas.
  Assign sound effects: From your bank of frequency wave-
forms produced in menu option 2, any 10 can be chosen for
instant recall at the touch of a button. Simply type in a
number from 1-10, followed by the number of the waveform.
When you now play the piano keyboard, each note will take
on the "flavour" of the sound effect chosen. Pressing
another of the keys 1-10 will change to a new sound effect
without interrupting the flow of music.

 Play sequence of notes

Compose riffs: It is often necessary to play a short riff -
sequence of notes - which is repeated many times and may be
complicated or fast. Synsounds allows up to seven riffs to
be stored simultaneously and then replayed by pressing a
single key. It is thus possible to give a creditable
musical performance with a minimum of stamina and skill.
On the computer keyboard in figure 1 the keys labeled (i)
to (vii) in the bottom row refer to these pre-programmed
riffs.
  After entering the number of the riff you wish to compose
(0-6), the Spectrum will draw up a chart of all the notes
playable - three octaves. Each note has a number 0-36 - 0
for the lowest C and 36 for the highest, and it is this
number tthat you must enter to place the desired note in
the memory. up to 16 notes can be entered in a single
program, but if fewer than this number are required then
typing 255 will complete the riff and return you to the
main menu.
  Longer notes can be entered by repeating the note several
times.
  Note that the riff will be played in the current wave-
form, so the 'flavour' of the riff can be altered by
pressing any of the keys 1-10.
  Sound produced only by the Spectrum's internal speaker
will rarely be of sufficient volume, so amplification can
be achieved by connecting the mic socket on the tape
recorder to the mic socket on the Spectrum and push down
the record button on the recorder.
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Figure 2.          | Figure 3.
  0123456789ABCDEF |   0123456789ABCDEF    0123456789ABCDEF
C                  | C                   C X  X    X  X    
B                  | B                   B XXXX    XXXX
A#                 | A#                  A#XXXX    XXXX
A                  | A                   A XXXX    XXXX
G#                 | G#X              X  G#XXXX    XXXX
G                  | G XX            XX  G XXXX    XXXX
F#                 | F#XXX          XXX  F#XXXX    XXXX
F                  | F XXXX        XXXX  F XXXX    XXXX
E                  | E XXXXX      XXXXX  E XXXX    XXXX
D#                 | D#XXXXXX    XXXXXX  D#XXXX    XXXX
D                  | D XXXXXXX  XXXXXXX  D XXXX    XXXX
C#                 | C#XXXXXXXXXXXXXXXX  C#XXXXX  XXXXXX  X
C X                | C XXXXXXXXXXXXXXXX  C XXXXXXXXXXXXXXXX
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