This album by Brian Eno, Music for Aiports, was designed to be precisely to be just that. It is ethereal music that was originally designed to be piped into LaGardia Airport in an attempt to defuse the tense, anxious atmosphere of an airport. If you want to be mentally be somewhere else, drift away into the ether, then this is the music for you.
I like to write to this type of music personally; others might prefer sleeping, barely breathing, or perhaps lowering their blood pressure.