HOWTO: Help! I upgrade my iPhone 4 to iOS 5 and now my music won'tplay on my phone!

Recently upgrade to iOS 5? Are you having fun exploring the new features but are not concern about other features still working? I recently upgraded and I found that my music did not restore properly. Some songs would play, others won't!

Don't worry. There is a solution.

Following the following steps:

1. Plug in your iOS device in iTunes and select the device. Under Summary uncheck "Sync with this.....". Under "Music" uncheck the "Sync Music"

2. Apply changes and let iTunes remove all the songs, don't worry!

3. Once that is all done all the music on the iOS device should be gone.

4. Now go back and check "Sync with this....." and Under "Music" check "Sync Music".

5. Let it sync and everything should be back to normal!

Cheers,

Source:
https://discussions.apple.com/message/16358617#16358617