Subject: Slide - further explanation

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.