Listening to music (not too loudly to annoy fellow passengers!) whilst staring out of the window on a brisk train journey is something I enjoy immensely. With its focus on rhythm, I find minimalist (and minimalist-ish) music can work very well for this. The best tracks I can think of are Divenire and Primavere from the album Divenire by Ludovico Einaudi, whilst an honourable mention must go to Michael Nyman's Musique à Grande Vitesse for what's probably an obvious reason on this forum.
(N.B. The links in this post are to Spotify.)
(N.B. The links in this post are to Spotify.)