Rosegarden's audio and MIDI mixer windows and main canvas can also be controlled to some degree by an external MIDI device. To set this up, you will need to use an ALSA MIDI connection manager such as qjackctl to connect your MIDI controller device to Rosegarden's "external controller" input and output MIDI ports.
Rosegarden accepts MIDI control change messages to adjust the mixer track corresponding to the incoming MIDI channel on each controller event, and also sends out MIDI messages when something is changed in a mixer track in order to support controllers with powered faders or knobs.
Rosegarden accepts MIDI controller number 81 to change the currently active window. Send controller 81 with data value 0-9 to select the main window, 10-19 to select the audio mixer window or 20-29 to select the MIDI mixer window.
Rosegarden accepts MIDI controller number 82 to change the currently selected track in the main window. The stepping of this controller depends on the number of tracks in the window -- the ratio of controller data value to track number will be calculated so as to use the full MIDI controller data range, provided there are no more than 128 tracks in the window.