Polly is listed for this music festival in Mexico, 10 & 11 October
right after her birthday and the book...

I saw that on Twitter as well, but I think it's more of a "wish list" (i.e. fake) - because I found this: http://mx.noticias.com/espectaculos/lis ... -2015.html.

Here's another (more believable, I think) line up:

These posters are false, every year share to the web fake posters of this festival until the month of June or July unveil the official, every year I attend this festival, the last year I watch Lykke Li and St. Vincent the same day, really do not think PJ Come to Mexico.