If you open your recycle bin, click View/Details, you will se a column headed Original Location.
That's where they were living before you deleted them, and where they will return to if you elect to restore them.
Presumably you are using something like iTunes or Windows Media Player to manage your tunes. If so, what you need to understand is that these programs don't store your files, they merely catalogue them, so if you delete a tune they remove it from the catalogue.
If you restore the tune, they won't know unless you also re-add it back into the catalogue (either manually, or by getting them to rescan your system for music).