Turning AMPLE hints into MIDI
Roger Sapolsky
MIDI users interested in a particular tip found in an
AMPLINEX issue may be disappointed when they discover that it doesn't work in a
MIDI environment. Let's take, for example, the case of the words 'swell' and
'fade' discussed in two articles by Neil Walker and Ted Kirk (AMPLINEX 021 and
022 Hints and Tips).
Suppose you wish to sustain the note C for a duration of 24
quavers, and also increase its sound level over the corresponding lapse of time.
First enter the words.
"x" [ GVAR ]
and
"y" [ 7 MIDICONTROL ]
Then insert the instruction which follows:
24, 10y C 10x #!
23 FOR( x #? y / 4 x #+! )FOR ^
23 FOR( x #? y / 4 x #+! )FOR ^
10 is the start level, 4 in the parentheses being the
increment added at each pass in the FOR(...)FOR instruction following the first
pass which uses the start level. The final level will thus be 10+22*4=98 in the
example given.
The instruction given is also valid for a 'fade'. In this
case, use a high start level, say 100 instead of 10 (127 being the maximum),
and put a minus sign before the increment, hence the final value 100-22*4=12.
Try -5 instead of -4: the level abruptly increases when the total becomes negative.
Let's have a look now at the article by Alan Minns (AMPLINEX
022), where he tells us how to eliminate the redundant note sounded in a
re-struck 3-note chord coming after a 4-note chord. In this case, the words
"n" [ 4 VOICE 128 VOL ]
"o" [ 4 VOICE 0 VOL ]
are also ignored when used in a MIDI piece.
Substitutes are in this case:
"n" [
N SHARE 4 VOICES MIDIV
nn MIDICHANNEL
mm MIDIPROGRAM ]
N SHARE 4 VOICES MIDIV
nn MIDICHANNEL
mm MIDIPROGRAM ]
"o" [ 4 VOICE UNUSED ]
Should the first chord following SCORE include 3 notes,
precede it with 'o' if it is repeated, to avoid the redundant note (for obscure
reasons, this note sounds an octave higher or lower than the first note
included in the chord).
Published in AMPLINEX 027, July 1992
