(sonicarts) some basic midi editing in logic pro x

We don’t have time to get incredibly in-depth with MIDI editing in Logic Pro X, but we should cover some basic techniques. I’ll also point out some traps to avoid.

track editing

Track editing of MIDI data is basically confined to region commands. You can create (empty) regions, loop regions, cut/copy/paste regions, and extend/shorten the length of regions. The pencil tool will draw an empty region. With the multitool capabilities enabled as described in a previous post, you can move your cursor along the right edge of a region to loop or change the region length. Changing the region length does not add any new material. When you loop a region, you will see MIDI data in the looped versions of the region. You can only edit, however, the data in the first instance of the loop. Editing the first instance of the loop will change the information all iterations of the loop.

Sometimes you will want to loop a passage with some data varied slightly. You can do that by using copy and paste for regions, instead of looping. Copies of regions can be edited independent of all other copies.

You can also click-drag regions in order to move them to other time locations, or other tracks.

piano roll editing

We used the piano roll window to view our step record data in process, and to add notes with the pencil tool. We can also edit the pitch of notes, cut/copy/paste notes, edit the length of notes, and adjust key velocities. I would recommend zooming in horizontally (time) for piano roll editing. You can also zoom vertically for pitch as you need.

You select the note that you want to edit with the pointer tool, either by clicking on a single note, shift-clicking on multiple notes, or dragging to select multiple notes. If you want to cut/copy/paste/delete, you can do so as you would with any text. For any single note selected you can edit the key velocity by dragging on the velocity slider in the bottom left of the piano roll window. You can adjust length (with or without first selecting a note) by moving your cursor to the edge of a note (the tool changes to the edge tool) and dragging to change durations.

If you select notes in the piano roll editor, you can edit and/or transform the selection in a number of ways. From the Edit menu (main menu or piano roll edit menu – both are the same), you can transpose the notes +/1 a semitone or octave. More powerful transformations are available in the Functions menu of the piano roll editor. From the functions menu you can quantize, apply fixed velocities, retrograde, invert, transpose by an arbitrary amount, or change dynamics. Choose Functions > MIDI Transform > for choices.

POTENTIAL TRAP: The piano roll only displays data for one MIDI region at a time, determined by what MIDI region is selected in the Tracks window. If you have more than one region in a track, select the region you want to edit in the tracks window. Other regions don’t even show in the piano roll editor.

It’s also helpful to close the piano roll editor when moving back to the tracks window. By doing so, you can open it again with the < cmd > + < 4 > keyboard shortcut. If you just click back on the tracks window then use the keyboard shortcut to open the piano roll editor again, you will open a duplicate piano roll window. Of course, you can use this multiple window option to display different MIDI regions at one time.

list editing

Maybe it is the programmer mentality, but I have always enjoyed list editors. You can see all the data for multiple notes, precisely as numbers. You can get to the list editor two ways: by typing < d > in the tracks window with a MIDI region selected, < cmd > + < 7 >, or from the piano roll window by double-clicking on any note.


All the edit and functions transformations are available in the list editor (like the piano roll). The list displays position as bar : beat : note division (in simplified form) : tick within division. Length is displayed in the same manner. You can change values, such as velocity, by clicking and dragging up or down on the number, or double-clicking and typing in a new value. You can move the playback head and insert a note (or any other MIDI data) at the playback head position.


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