Music app gets stuck when trying to switch songs help pls

I don't have a lot of songs on my phone, maybe 1500, but lately I've had to restart my phone often because when I try to change tunes midsong, the app gets stuck, and if I keep trying my phone just locks up and I can't switch screens at all. And today, it got worse. When I tried to play a new tune, the album cover of the new tune would show on my screen, but when I press play, it would play previous selections, 1-2 songs previous.

Example - played Tarantula by Smashing Pumpkins, stopped it, and then played Lump by Presidents of the USA, the screen brought up the song and the artist name and the album cover, I pressed play and Tarantula played again!

This happened more than once. I would turn off my phone and start the music app and same thing. I gave up for now and just listening to Pandora instead :( Usually, when I have issues with app, I just delete it and download it again, but I can't do that with this one. I don't know what to do. Would appreciate suggestions. Thanks!