If I'm doing focused listening on the music, the sound quality is surprisingly unimportant - so long as nothing is horribly off I'll be OK because I'm focusing on the music itself and my mind is able to do a tremendous amount of "error correction" for less than optimal sound quality. If I'm doing focused listening on the sound quality, then of course the sound quality is everything.
SFL - the best kind of listening in my opinion in terms of listening for sound quality. I become less judgmental of sound quality and generally enjoy myself a lot. I do notice sound quality in this setting, so it's still fairly important. As long as there are some noticeable good qualities to the sound I'll get a lot of enjoyment, picking up on the good without being very critical of the bad. I think I enjoy music the most in SFL too. Music can be listened to as a total point of focus, but it often works so well to enhance other activities when attention is shared between the two that I think I have richer overall experiences that way.
CL & AL As long as it's not screeching horrible sound quality doesn't matter too much in these settings for me. It's still nice to have some quality though.