Welcome to Android Central! Which music app are you using? Have you tried different music apps? Are you playing locally stored music, or streaming from the cloud? Are you getting error messages, or is nothing happening at all?
It's just my general music that I download onto my phone via my laptop and it just won't play I have had the phone since November and its never not played before
Which music app? Have you tried other music apps? Do you get an error message? Where are the music files stored on the phone--Internal Storage or the microSD card?
I think it is internal storage and it isn't an app it is the general music (play music is wat it is called on HTC's ) it's an app that u can't delete or re-install like contacts, or messages it is an app that is already on the phone when u get it
It's important to know if the music is on Internal Storage or the microSD card, because SD cards can become corrupt or fail--that could be a reason why Google Play Music can't find the music files. Use a file manager app like ES File Explorer and look for where the music files are located on the phone.
You can also try another music app and see if that recognizes the music. Try Rocket Player or MortPlayer Music.