How can I take a section of midi and halve all lengths then tighten the gap in-between the notes so that it sounds like it is being played at double the tempo (without doubling the tempo of course).
For example, say I have a long phrase a mix of quarter-notes and eighth-notes played legato at 120 tempo and now want to repeat the same legato phrase now expressed as eighth-notes and sixteenth-notes played legato at 120 tempo.