Today, I’ve discovered that Hydrogen 0.9.3 contains a hidden piano roll note’s pitch editor that you can enable by:
1) running hydrogen
3) editing ~/.hydrogen/hydrogen.conf
4) replacing <usepitcheditor>false</usepitcheditor> with <usepitcheditor>true</usepitcheditor>
5) running hydrogen again
Now, in the UI, you’ll notice a new button under «velocity» in the note editor.