I know that it can't be learned, but that something really close can be earned. I also knew a few folks with PP who did not view it necessarily as a gift, also, so I never thought of it as a must-have to be a musician. One girl I knew had a terrible time playing in the orchestra because the strobe tuner they had was off a bit, and the band director just didn't even try to fix it, so she was miserable every time they played a song, and also she could not make herself tune out of tune, so it seemed to be more a great big PITA to her than anything else.
And maybe PP is more than one thing. I can't say.
I've also heard people say that PP was problematic for them at times. I wonder if something like eidetic memory has a downside? The show "Unforgettable" is about highly superior autobiographical memory and that seems to have it's pros and cons as portrayed in the show. So far there's been been no downside with synesthesia for my kid, she can't imagine life without it.