Default Does This Music App Exist ?!

I just wish to say I'm not requesting an app to be built but inquiring if this app exists. The app I'm looking for is a music app which instead of reading MP3 files on the SD card, it natively stores the music and onto the app so their only read by the app. In other words If I was to go on my default music player, I wouldn't be able to find the music which is playable only the app ?!
Does something like this exist ?!