That's true, but the point is that this correlation could be pure coincidence, or at least not causative. (If it actually occurs to start with - it would be interesting to create a poll and verify whether most reputed programmers are indeed more musical than general population.)

Many programmers have stereotypical geek interests like RPG, Star Wars etc. but it doesn't mean that these contribute to their programming skills in any way. Being socially awkward doesn't make you Sheldon Cooper :)