Merging downloaded Iphone music with my synced list on the device

[nostracorvus]

Hi, sorry if this is in the wrong place. I've got some music I downloaded plus my regular synced list. The app has its own built in player which will only see the music I've downloaded much like the Apple player only sees my synced list. Is there an app that will play all mp3s on the phone? I'm on the latest update so I'm not jailbroken. Just curious if anyone has an answer or suggestion. Thank you! Iphone 4 8 gig.

 

[Pinkpoison]

Moved your post here for better help.

 

[nostracorvus]

Thank you!