As I have mentioned in earlier posts, mixing is a large part arranging. Showing people different things as the song/song set progresses. But mixing is also hiding things. It’s not only a “look here, look there – hear this, here that” but “don’t hear this, don’t look there”.
I recently was working a gig where at the end of the speaking part, the speaker asked a musician to perform a specific song. Earlier in the music part of the event, the musician (a guitar player/singer) had broke a string on his guitar. So during the speaking part, he replaced his strings. When he got back up to perform, he realized that the guitar had gone out of tune and was frantically trying to tune. The speaker kept pushing him to start, so finally, he did. Unfortunately, he hadn’t finished tuning. So here I was mixing. I have a performer playing slightly out of tune and therefore singing out of tune (in tune to his instrument). I could hide his instrument, but not his voice since he was the soloist. So I opted to ditch all of the other instruments except the rhythm section. It became an almost guitar solo with vocal, bass, and drums. Eventually, the song went into a freeform mode where I could lose the guitar and add the rest of the instruments. And soon after, the performer realized that since it was freeform he could stop for a minute and finish his tuning while the band vamped. Then the world was back in order.
The point is that I could just have let it be what it was because it was no fault of mine that the player was out of tune. But I did a creative arrangement decision that concealed to most of the audience the train wreck happening in front of them