Replace software instrument recordings in Logic Pro for Mac
When you’re recording, you can replace all or part of a previous performance while recording a new one. You do this by recording in Replace mode. You can choose one of the following Replace mode behaviors from the Replace pop-up menu:
Region Erase: Erases MIDI regions from the Tracks area across the entire recording, even if nothing is played.
Region Punch: Erases MIDI regions only where MIDI events have been recorded.
Content Erase: Erase only MIDI content inside of MIDI regions, across the entire recording, even if nothing is played.
Content Punch: Erase only the MIDI content inside of MIDI regions, but only where MIDI events have been recorded.
You can access the Replace pop-up menu by clicking and holding (or right-clicking) the Replace button 
in the control bar or in the Recording Settings pane.
Note: For information on replacing audio recordings, see replace audio recordings.
When Enable Complete Features is selected in Logic Pro > Settings > Advanced, replace recording is available.
Record over an existing MIDI region
In Logic Pro, click the Replace button
in the control bar.Drag left or right in the top part of the ruler.
The cycle area appears as a yellow strip in the ruler, and Cycle mode is automatically turned on.
Click the Record button
in the control bar (or press R) to start recording.Recording starts automatically at the beginning of the defined cycle area.
Use your MIDI keyboard, Musical Typing window, or onscreen music keyboard to play some notes. Record as many cycle passes as you want.
Click the Stop button
in the control bar (or press the Space bar) to stop recording.A new MIDI region is created on top of the existing one in Region Erase or Region Punch modes. The content of the existing region is replaced in Content Erase and Content Punch modes.
Click the Stop button in the control bar (or press the Space bar) to stop recording.
Your new recording now replaces the previously recorded portion of your material.