Interpretations religious, alchemical, historical, and evolutionary.
You're free to speculate as you wish about the philosophical and allegorical meaning of the film—and such speculation is one indication that it has succeeded in gripping the audience at a deep level—but I don't want to spell out a verbal road map for 2001 that every viewer will feel obligated to pursue or else fear he's missed the point.
The movie eschews and engenders intellectual verbalization e.g. allegorical references to Homer's epic: Bowman as Odysseus, skilled archer; one-eyed HAL as Cyclops, killed by Bowman by insertion of a key just as Odysseus blinds Cyclops with a stake.
(Check award winning http://www.kubrick2001.com/ for orthodox reading)
Music has synchronous meanings. Nietzsche's Thus Spoke Zarathustra is referenced by Richard Strauss's music of the same name. Zarathustra posits humankind as rope dancer balanced between ape and Übermensch.
Further Nietzschean conceit comes from The Birth of Tragedy and the conflict between Apollonian and Dionysian modes of being. Apollonian is for rational, scientific, and self-control. A purely Apollonian mode is problematic; it undercuts the instinctual side, lacking wholeness and immediacy. While the ape world at the beginning of 2001 is Dionysian, space travel is wholly Apollonian, and HAL an entirely Apollonian entity. Johann Strauss II's coolly syncopated and mechanically driven waltz kicks in during the space station docking scene.
We also get Gyorgy Ligeti's sublime atmospherics....go figure. Wherever it takes you, this soundtrack will make your day seem significant and weird.
Tool up (or tool down?)....
Oddi wrth y brawd