I put this together today. The melody is something I dorked together a couple days ago using “midikeys” and “simplesynth” to play a soundfont into ardour while a click track played in the background. Today I designed a a drumbeat to go with it. It was trippy — once I set up the synchronization between Jack and Hydrogen as described in the tutorial, not only did hydrogen start playing when I started recording in Ardour, but when I started playing my Hydrogen stuff while I composed it, it triggered my melody to play in Ardour! So I could put the drum track together in Hydrogen and have the melody play in the background in sync with the patterns I was composing. Neat.