Demixing MIDI Regions

It is not unusual to record MIDI drum parts by triggering multiple sounds in a single pass, creating a single Region containing both instruments. This technique can benefit bass drum and snare parts, helping to create a part that locks into a groove. However, having the kick and snare in the same Region can make it more difficult to edit those parts independently, as any modifications done to the Region will be applied to both parts.

Because MIDI is a stream of commands with discrete events, it allows for some fancy editing functions. One such function is demixing, which enables you to divide a MIDI Region into separate components based on specific criteria. You can try this on the bass drum/rim shot part, splitting them into separate tracks for independent editing.

1.	Press the number 4 key to bring up Screenset 4. The screenset contains a Matrix Editor and an Arrange window.
2.	In the Arrange window, select the BD/Rim Shot Region in Track 6. The Matrix Editor displays the content of the selected Region. Within the Matrix Editor, you can see the bass drum (C1) and rim shot (C#1) parts represented as notes. Let's separate the two parts by using a handy feature accessed from the Arrange window.
3.	From the Arrange window's local menu, choose Region > Split/Demix > Demix by Note Pitch. The Region on Track 6 disappears and is replaced by two new tracks with corresponding Regions.
4.	Click the background of the Arrange window to deselect any Regions.
5.	Click the Region in Track 7. The Matrix Editor displays the bass drum events (C1).
6.	Select the Region in Track 8. The Matrix Editor displays the rim shot events (C#1). When using the Demix by Note Pitch function, a new MIDI track and a new Region are created for every note number found. In addition, the newly created tracks are automatically assigned to the same instrument as the original MIDI Region. For easier identification, name the new tracks and Regions with their corresponding instruments.
7.	Select Track 7 (if it's not already selected).
8.	Choose Track > Create Track Name.
9.	Enter Bass Drum in the text box, and press Return.
10.	Select Track 8.
11.	Choose Track > Create Track Name.
12.	Enter Rim Shot in the text box, and press Return.
13.	Select both Regions by rubber-band selecting around them.
14.	Choose Region > Track Names to Regions. The Regions take the names of their corresponding tracks.