I needed about a minute of ambient music and this is what happened. Three chords repeated with slight variations. Mostly stolen from Bach’s Prelude in C. Type these into MuseScore. Render in to WAV in MuseScore with samples for “strings”, then with “ooh”, then with “bassoon”. Copy these to Reaper. Cut some parts from “ooh” and “bassoon” so these come in later. Add generous reverb and some delay. Done.
Funny thing is that, depending on the listening environment, additional ghost instruments appear. For example on iphone earbuds I hear trumpets at the end. I think because of all the overtones (harmonics) and how they randomly interact with each other when the same notes are rendered with different samples and different delays and reverbs. Spooky.