I’m not a lawyer, but I think the “terms of service” for Spotify are more restrictive than is generally assumed. For a definitive answer you would need to trawl through this lot: https://www.spotify.com/us/legal/end-user-agreement/
I’ll leave that for you to figure out / decide, so let’s just look at the more general issue of splitting long recordings into separate tracks/songs: http://manual.audacityteam.org/man/splitting_a_recording_into_separate_tracks.html
I presume that you do that with iTunes, in which case this may also be useful information: http://manual.audacityteam.org/man/tutorial_exporting_to_itunes.html
Of course you are entitled to use their Listen offline service (downloading playlists as DRM’ed cache that you can listen to in the Spotify app).
Downloading in that limited sense is not the same concept as recording (transferring by playing) which is stated as not permitted in the terms of service.
Gale