To edit recorded sustain pedal events in GarageBand, open the MIDI region’s Piano Roll Editor, show region automation, and select Sustain. Adjust the recorded points there; use the Score Editor when you want to delete pedal markings.

Apple documents MIDI controller editing through region automation, including adding and adjusting points with the same techniques used for track automation. This guide focuses on correcting pedal timing in an existing software instrument recording on Mac. Use automation in the Piano Roll Editor in GarageBand on Mac

Open the recorded region and find its sustain data

Begin with the MIDI region containing the performance you want to correct. Double-click it to open the Piano Roll Editor below the Tracks area. You can also select the region and click the Editors button. Check the editor header to confirm the intended region is selected; Apple says the header identifies the region or indicates when several regions are selected. Intro to the Piano Roll Editor in GarageBand on Mac

In the editor’s menu bar, click Show/Hide Automation. Apple also documents the shortcut A. Using the button makes the location explicit when you are moving between the main arrangement and the editor. The automation lane should appear below the notes, with an Automation Parameter pop-up menu and a Cycle Through button in the inspector. Select Sustain for the recorded pedal data; the cycling control lets you inspect multiple existing automation lanes. Show automation in the Piano Roll Editor

Before changing anything, identify the recorded press and release around the passage. Note their positions against the ruler and the nearby note endings. For this task, first preserve the recorded values and change timing only. That keeps the edit focused: you are deciding when an existing pedal action occurs.

If you need more space, drag the bar at the top of the editor upward. Its ruler provides time divisions, and its zoom controls help you inspect closely spaced events. Work on one region initially so that nearby material does not obscure which passage you are correcting. Resize and navigate the Piano Roll Editor

Move a pedal press or release to the right time

Apple’s automation instructions distinguish two movements: dragging a point horizontally changes its timeline position, while dragging vertically changes its value. Numerical values appear beside points during editing. For a timing correction, drag the existing point left or right and use the ruler to judge its new location. Add and edit automation points in GarageBand on Mac

Use this sequence for a focused correction:

  1. Find the pedal action immediately before the unwanted sustained passage.
  2. Identify the release that follows it.
  3. Move the event responsible for the timing problem horizontally.
  4. Keep its vertical position unchanged initially.
  5. Play from before the press and continue past the release.
  6. Inspect the following pedal action before making another change.

For example, if a release happens later than intended, move that release earlier. If the entire pedal interval is misplaced, move both its beginning and ending. Moving just one boundary changes the interval’s duration. This is a practical editing distinction derived from treating the two recorded actions as the boundaries of the passage you want to sustain.

When a value also needs correction, drag the point vertically. Apple documents holding Control while dragging for finer value adjustments. For ordinary press-and-release repairs, existing recorded values provide a useful reference. The cited GarageBand instructions do not specify a sustain-value threshold, so this workflow does not depend on an undocumented numerical cutoff. Adjust automation points

Work through a synthetic three-note example

Consider this illustrative passage in a four-beat bar: C4 begins on beat 1, D4 on beat 2, and E4 on beat 3. Each note lasts half a beat. Suppose the recorded pedal press occurs just after beat 1 and its release occurs just after beat 4. Your intended result is to release the pedal just before E4 begins. These are invented teaching inputs, not a measured recording or a prescribed musical pattern.

What you observe First edit to try What to check afterward
The pedal release is after beat 4 Move that release to just before beat 3 Play through the transition into E4
Both press and release occur too late Move both boundaries earlier Confirm the interval still has the intended duration
A brief unwanted pedal interval appears between notes Inspect both boundaries before removing it Confirm the surrounding intended intervals remain intact
The passage still sounds too long Inspect note lengths as well as pedal data Decide which recorded event actually needs changing

In the first case, leave the press where it is and move only the release. Then replay all three notes. Starting before the press gives you a consistent way to compare the full sequence, rather than judging the result from a single isolated moment.

If the result still differs from your intention, inspect the note bars. Apple documents resizing MIDI notes by dragging either edge horizontally, with a help tag displaying length. Use that operation when the note’s recorded duration needs correction. Keep note-length edits separate from pedal edits so you can hear the effect of each change. Edit notes in the Piano Roll Editor in GarageBand on Mac

Remove unwanted pedal events without removing the notes

Apple documents selecting an automation point by clicking it, extending a selection with Shift-click, and deleting a single point by double-clicking it or selecting it and pressing Delete. Its region automation page directs readers to the track automation techniques for point editing. Start with individual points when repairing a small passage. Copy and move automation in GarageBand on Mac, Use region automation

Before deleting a point, inspect the neighboring press and release. Removing one boundary may produce a different sustained interval from the one you intended. If the goal is to eliminate a complete accidental pedal action, examine the whole interval and replay the transition afterward.

Apple also provides an explicit notation-based deletion path. Select the MIDI region, click Editors, and click Score to open the Score Editor. Apple states that pedal markings can be deleted there. Select the unwanted marking and use Edit > Delete or Delete, checking the selection before acting. Intro to the Score Editor in GarageBand on Mac, Edit notes in the Score Editor in GarageBand on Mac

Deleting notes is not a reliable controller-cleanup method. Apple explicitly says MIDI controller information can remain after the notes recorded with it are deleted. For multiple automation-point deletions, Apple also warns that selected regions may be deleted with the points. Inspect the active selection carefully and keep the operation limited to the events you intend to remove. Score Editor deletion behavior, Delete automation points

Understand the documented capability limits

The supported editing path is graphical region automation: display recorded controller changes, adjust their timing or values, and add or remove points using Apple’s documented automation techniques. The Score Editor provides a documented alternative for deleting pedal markings. These instructions establish a usable path for repairing recorded sustain events.

The cited GarageBand pages do not document a numerical MIDI event-list workflow, a sustain-specific half-pedal calibration procedure, or guaranteed identical pedal response across instruments. Those are limits of the documentation used here, not proof that every unmentioned behavior is impossible. Avoid assuming that a visible intermediate value establishes a particular half-pedal response.

Apple’s current Mac release-notes page lists GarageBand 10.4.14. It also records a fix in version 10.4.4 for MIDI sustain events responding when playback starts at different timeline positions. If an older installation behaves inconsistently depending on where playback begins, that documented history is relevant to troubleshooting. GarageBand for macOS release notes

Finish by replaying from before the first edited press through the following release and into the next notes. Check that the intended note lengths remain, that each pedal change occurs where you planned, and that neighboring intervals still work. Once the passage matches your intended timing, the correction is complete.

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