Toggle Channel Strip Mute M — Logic Pro keyboard command of the day

  Toggle Channel Strip Mute M

Alternate the state of channel muting, on and off. I am getting somewhat inconsistent results when using the command in the Tracks window. Sometimes the selected channel does not toggle.

Mute and solo channel strips in Logic Pro — Apple Support

You can silence (mute) a channel strip so that you don’t hear it when you play the project. Muting channel strips is useful when you want to compare how the project sounds with and without the target track, compare alternative versions of a track, or try different loops in a project.