Can anyone advise whether a DJ mixing app exists that allows audio files to be imported via Apple Configurator?

All of our iPads are supervised using Apple Configurator, hence they cannot be synced to iTunes. I have tried installing the following apps:

djay (By algoriddim)

Traktor DJ (By NATIVE INSTRUMENTS GmbH)

DJ Mixer (By Musicsoft Arts)

iDJ (By Numark)

However, none of them appear to allow importing of audio tracks via Apple Configurator. I am using the 'assign' feature, and adding MP3 files to each app individually.

Is anyone able to help?? I'm willing to buy any DJ app if it will work!!