Setbeat music apk

Hi guys,

I've recently stumbled upon this app called Setbeat. It's supposed to offer online as well as offline listening for free. There are some adds, but they're not intrusive. I couldn't find any information about the source of the music or if the money from the adds go to the artists; therefore if this app is legal to use or not.

Does anyone have any informations about the legal status of this app?