To set up your Keyboard Maestro "Pitch Pipe" group to activate with Option+Return, stay active while you play notes, and then deactivate after 10 seconds of inactivity: create an "Idle Timer" macro within the "Pitch Pipe" group that pauses for 10 seconds and then deactivates the group. <a href="https://www-dqfanfeedback.com">Official Site</a>