hmm, I’d not really think of it like that…
T16 is used for transposing all other tracks (that have MTSP set) by the number of semitones from C3.
these tracks will use the scale that is on the individual tracks, which could be the project scale (pScale) ,or might be set on an individual basis (e.g. using Scale FX)
note: the latest firmware fixed a bug where transposition was not taking into account pScale.
I think the issue some are having is a confusion between transposition and changing keys/scales…
its not the same thing.
sure if you turn off pScale, then transposing will change the scale you are using.
but. pScale on, then you are still fixed to that scale… in this case really you are changing modes.
if you really want to transpose to a new root/scale (e.g. move from C Major to D Minor), then not only would have to transpose, but you would also want to use Scale FX , so that can you alter the scale of the track.
(again this slightly depends upon what you are trying to achieve musically)
how to use in practice…
sure, for live performance you might want to ‘play’ the transposition track.
but if you are building a song, then you probably want to sequence T16, so you put a pattern where (eg) the first note of the track transposed to the new transposition…
you could of course then included these pattern changes in a ‘song/section’
and as above you may want to be automating the scale fx, if you really want to be transposing to a new scale, and need notes to be quantised to that new scale.