Offset modulation changes the time offset of a target track. The supported target types are note tracks, controller tracks and modulator tracks. For note and controller tracks, an offset modulator's steps are interpreted as unsigned delays in MIDI ticks. By default, events can only be made later, not earlier, but you can work around this by setting the target track's offset to a negative value. For example if the target track's offset is −64, that gives its offset modulation an effective range of −64 to +63, in other words from 64 ticks early to 63 ticks late.
Offset modulation changes the rhythmic feel of the target track, periodically speeding it up and slowing it down relative to the beat. It can be used to create rolls on drums, or to emulate the feel changes of a live performer. For best results, use a smooth function such as a triangle or sine wave. Sharp changes in offset modulation may alter the order of events. Offset modulation can cause notes to overlap.
Modulator tracks can also be offset modulated, but in this case the offset modulator's steps are interpreted as signed values, allowing offsets in the range of −64 to +63. Positive values delay the target; negative values hasten it. Offset modulation is useful for time-shifting a group of modulators that have different quants. Offset modulation is similar to position modulation, except that the shift is specified in ticks instead of steps.