From the manual:
To mute or unmute several events, select them – either by using the standard selection techniques, or by using one of the options on the Select submenu on the Edit menu – and click on one of the selected events with the Mute tool.
All selected events will be muted.
Does NOT work…
Selecting multiple events, and then clicking on one of them with the Mute tool mutes ONLY the single event.
Keying “shift-m” mutes them all, which works fine (IF I can remember the key-command), but does anyone know why the mute tool doesn’t work properly?