What is the Lisp function for stopping playback (bound to the shortcut cmd-esc)?
... I could never add a custom keyboard shortcut to the Opusmodus text editor Hemlock (and I tried), but I just managed adding keyboard shortcuts and a menu for playing Opusmodus snippets and my polyphonic score format to Emacs (thanks to the fact that scores now can be displayed in a separate window). Only need some key for stopping playback as well.
(The main thing I will then miss when using Emacs as the Opusmodus IDE is the close integration of the document, but well, you cannot have everything 🙂 On the plus side, I have a more stable editor and in particular a very good debugger.)