Since moving my music "to the cloud" in Apple Music and running short of storage space on my iPad with all my Synth software, I find that I don't have nearly as much music to listen to on long flights. When I want to zone out or relax on cross-country flights, I like to have some ambient or low-key music to keep in the background while I'm semi-conscious. Without sufficient studio time to craft lots of harmonies and voices, its software to the rescue. I used generative music apps to create evolving melodies for each leg of the trip.
I put together a baroque repeating piece on my way to LA which came out as the following:
I used the very interesting Fugue Machine to put together a sequence of notes played on the Rucker Harpsichord app in 2-3 separate voices in differing tempos. Periodically, I'd use the software to invert, mute and/or mangle each of the voices. While the result is a bit "busy", I think it came out ok. Nice when kept on repeat.
On the way home I went to some old favorites using Noatikl, the Korg iM1 and MultiTrack DAW. For the return, I programmed a pad voice, a bass and a lead all using separate MIDI channels in the iM1. This one did have the desired zoning effect and kept the background noise (lots of that in economy seating) at bay.