Alan Minns
The problems and difficulties associated with the use of
Slide, due in no small measure to the inadequate and misleading example in the
Music 5000 User Guide (sorry, Hybrid), have arisen more than once in AMPLINEX.
Mr Richardson (AMPLINEX 023 Features) seems to have solved
the problem although not entirely to his complete satisfaction. May I therefore
try to fill in one or two gaps?
The primary point is that ON Slide and OFF Slide are
essentially brackets of a special kind. Inside these brackets, the symbol 'L'
changes its meaning from referring to a dynamic level to referring to a pitch
shift or offset measured in quarter-semitones. One important point is that ON
Slide does NOT set the offset to zero! If it is not defined inside the brackets
(e.g. 24=L), the offset which is used in the Slide is the numeric value of the current
dynamic level.
So, by defining an offset of 24=L, the sound will start
24/4=6 semitones above what is expected, or below for -24=L. Then 24 8 -L or 24
8 +L will give a fall or rise in pitch to the 'normal' value over 8 beats of
the current note length. The note length as defined by the comma setting, is typically
'1,' which is something like a third of a hemidemisemiquaver (for the usual
crotchet setting of 48,).
To calculate the correct bar length, consider the usual
specification of 48, 4 BAR which gives a bar length of 192. Taking the
essential data from Mr Richardson's example, we have:
1, F 23 FOR(/)FOR 24, ////^
This amounts to a length of 1*(1+23)+24*5 = 144. To complete
the bar 192-144 = 48 or two more holds at the current 24, setting.
I hope only that the above does not further the confusion.
Published in AMPLINEX 024, January 1992
