I definitely only store metadata about music in my head. I can think of a piece of music that I know very well and quite easily 'construct' a mental facsimile of the original. Attributes that stick easily with me tend to be phrasing and timbre of instruments. This means that if I really, really know one particular recorded version of a piece I am unable to 'experiment' with different styles, artists etc.

Shame, really, I always wanted to hear Swarbs playing the Double Concerto...