what happens if i restore my phone as new

Have you tried a reset?

Then try a restore from backup.

The try restore as new if neither works.

A restare as new will make your iphone as it was when it was new.

Some things I know happen when you restore as new (not a complete list):

1. You have to re-do all your Setting preferences that deviate from default.
2. You have to re-do all your sync settings for each media type.
3. You have to reload all your media.
4. You lose prior text messages.
5. You lose call history.
6. You lose any app data, such as progress on games, favorite cities for Weather, etc.
7. Your Camera Roll re-starts blank, so first make sure you copy Camera Roll content to your computer.
8. Your photo counter re-starts, so copying pictures from Camera Roll to your computer will result in duplicate file names if you save them to the same folder each time.
9. Your Contacts are not part of your backup anyway, so make sure you have them stored somewhere (on your computer or a web service like iCloud, Google, etc.)

There are probably many things I'm leaving off. Before restoring, try other things to fix your music issue if you have not tried already:

1. Reset
2. Restore from Backup (does not erase iPhone)
3. Restore, then load last backup (erases iPhone, but re-loads everything but your Contacts)

If that does not help, then Restore without loading a backup is your last resort.