This will help, but counts on which iPhone you have
1. Open Folder Options by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, and then clicking Folder Options.
2. Click the View tab.
3. Under Advanced settings, click Show hidden files and folders, and then click OK.
after this is done plug in your iPhone and go to my computer and click on you iPhone and you should be able to view the hidden folders in the iPhone and your songs are there.(they are named weird but when you drag them into the iTunes they will be normal again)