The logline meets the criterion for brevity. And “delves into the dreams…” tells us what the musician does — well, sort of. What exactly does it mean to delve into another person’s dreams? Whatever it means, it seems rather vague, subjective, and intangible.

There seems to be the ingredients for the “B” story line of a movie — the love story, the romantic relationship. But a logline is primarily about, the “A” story line. And the “A” story line is about:

1] A protagonist (usually) with a flaw
2] Who struggles to achieve a specific (as opposed to vague) objective (as opposed to subjective), tangible (as opposed to intangible) goal.
3] A clearly defined antagonist or obstacle.
3] A sense of the stakes: what the protagonist stands to gain if he succeeds, loses if he fails.

Hope this helps. Good luck with your story.