Obviously we're listening to the sound and music simultaneously, the two are inseparable. Which is most salient at any moment in time is the question. I can't recall a single listening session over many decades of listening to high end systems when sound quality or qualities didn't rise to primacy at certain times. This mostly due to the high variability in recording quality, how one could ignore the often extreme differences in sound quality between recordings seems unfathomable. The only time I can ignore this is when listening on midfi systems like I have at work or in cars, these systems homogenize recordings to a large extent
. I'm also very content listening to mediocre recordings, being attentive to the sound doesn't have to be a necessarily judgmental exercise. Beyond this, paying attention to sound quality can quickly morph into the music and/or performance of that music rising to primacy, I don't listen in only one unchanging mode.