The .nomedia file makes it so the pictures are not indexed and added to the gallery, it does not affect the scan of the mp3s themselves. They should be being added to the index of available music which is what the players look at to find music.
First restart your phone to force an index and see what shows up if you have not already done it. I know it sounds obvious but make sure the music is in a format that the player can read. It does all the usual stuff like aac, mp3 and so on but if you've gone into one of the more unusual lossless formats or whatever you have to get a player that can play that format. Related, make sure that you have not imported your music to your phone in a play list format that the player cannot play. Both of these get people all the time.
If you have already restarted and the files can be played by the player and are not in an unrecognizeable play list then the next step is to go into your settings/applications/ find the player and delete its cache and data. Force stop it and then restart your phone. Startup will take slightly longer than usual but thats normal. This will not delete your music. If that doesn't work let us know.