To save the master piano tuner she loves, Violette must face her unbearable ability to see sound as colour. -This says romance to me! -
I think you still need to brainstorm the second sentence. I like the damned part because it gives your pitch a dark phantom of the opera touch. If you just say she risks losing him forever, it's in any romance novel. I'm not sure how to work it in, though.
When a master piano tuner manipulates music, Violette must face her unbearable ability to see sound as colour. If she can't see past her painful memories, the man she loves will be damned forever.