For me, it's quite a complex issue. I guess that as I've developed my skills as a musician, I've begun to be able to appreciate music on an additional level. Maybe "appreciate" is the wrong word. "Assess" might be more appropriate. Since I first seriously got into music when I was 16, I've appreciated music in the way that every music-lover does. After I took up an instrument and developed my musical knowledge, I was also able to appreciate things like song structure, technicality and various other esoteric elements of muso wankery. However, this side of my listening has always been secondary to music-lover in me. For example, some of my friends assume that I only like jazz and "prog" because I'm a musician, and can appreciate the technicality involved in playing such styles of music. Nonsense! It doesn't matter about the potential for chin-stroking muso appreciation, if a piece of music doesn't sound good, it doesn't sound good. In other words, if something is technical for the sake of being technical, it does not make for good music. So I can choose to pick apart a piece of music, assessing the various techniques and tricks utilised by the composer and the performer. But whether I'll enjoy listening to that piece of music is entirely dependent on the listener in me, rather than the musician. I've always had a taste for innovative and interesting music, so I think I'd be listening to the same stuff I listen to now even if I hadn't taken up an instrument. Also, although I'm a bass player, it's not always bass that I listen out for. Drums and piano in particular are other instruments that I can really appreciate when listening to music.