Some GarageBand users have encountered a problem when editing Software Instrument tracks. They report that they are unable to trim the start of regions in these tracks.

GarageBand does not allow you to trim the beginning of a Software Instrument region before the first MIDI data event, whether it’s a note, a controller movement, or any other MIDI event.

Here’s an example:

You record a region using any of the Software Instruments in GarageBand. If you then try to “trim” the beginning of the region to line up with the first note played, or the downbeat of the measure, you find you can’t drag the left edge of the region to the first note of music. You may either be able to trim just a part of the region or not to be able to trim at all.

This is because GarageBand does not allow removal of MIDI data from the beginning of a region using the trim function. The solution is to split the region at the beginning of the note data and then delete the first segment. Here’s how:

1. Select the region you want to split.

2. Move the playhead over the point in the region where you want to split it. In this case it should line up with the first note or other piece of MIDI data.
3. Choose Edit > Split.
4. Select the empty region that’s been created and press the “Delete” key.

Only the selected region will be split, even if a region in another track is under the playhead as well. The selected region is split into two regions at the playhead. When you split a Software Instrument region, any notes at the split point are shortened to that point. NOTE: If you have selected multiple regions and they are under the playhead, they will all be split.