When viewing music notation in GarageBand 2, the notation that represents a MIDI recording or loop may not always match the exact rhythm that you hear. This happens because rhythmic values are sometimes rounded up to a longer value.
For example, a section of sixteenth notes may display as eighth note triplets. (To view the notation display, double-click a Software Instrument loop or MIDI recording—any green region—to open it in the editor, then click the music note button in the editor's Region pane.)
GarageBand allows you to adjust the notation display grid to make the music more readable, and it quantizes the display without affecting the actual sound of the recording, since (in most cases) you won't hold notes for their fully displayed values. This can help when you play a series of staccato notes, for example. You can adjust the display to show them as eighth notes rather than as a combination of thirty-second notes and rests.
To adjust the display grid setting, click the grid button in the upper-right corner of the Notation Editor (the button that looks like a ruler to the right of the measure bar). A pop-up menu appears, listing the available note value settings. Choose a value that will allow the shortest notes in your selected recording to be displayed. The notation display will round up the displayed duration of all notes to the nearest time division as determined by your grid selection.
For example, if you make a MIDI recording that contains sixteenth notes but set the grid to eighth notes, the display will show groups of sixteenth notes as eighth note triplets because this is the closest rhythmic value it can display at that grid setting. Keep in mind that your recording will always sound exactly as you played it—no matter what grid setting you choose here; only the visual display of the notation changes.