Try thinking of it as just 0's and 1's. Really it just comes down to what audio you can make with a certain allowed number of bits. Anything that would be possible to be recorded into a 5 minute CD audio file is in that finite number. One of those possible combinations of 0's and 1's is the audio recording of me listening to myself listening to myself listening to myself reciting the Gettysburg Address in Icelandic while playing golf on Mars.. Seems impossible, and that surely it would have to have infinite possibilities, but when you really think about it, there MUST be a limit to how many unique 5-minute audio files there can be.

Phenomenally interesting topic! Vsauce brought me here. ;)