I get where Rich Hickey is coming from, but his analogy does have gaps. Not every piece of music is for a cello, and in fact, much of it is for discretized and not continuously pitched instruments such as pianos and guitars, which also take out the variable of bowing.

The innovation of discrete pitch was practical -- for many songwriters, the point is to get out the song and not focus on "implementation details" -- and I think there are a lot of similarities there to software.