Miles Davis' landmark Bitches Brew was a double album containing only six cuts - all six meet the definition of "long song" used in this thread, but the 4:22 "John McLaughlin" stands out for its brevity. All five of the other songs are over 10 minutes; two of them are over 20 minutes. The title cut clocks in at 26:58. It was written as a 5 part suite, but only three are used on the album because that was all that could fit due to the technological limitations of the time.