Hey thanks for the tip - found the link to the competition...
I play and record live on an android tablet, stream music in the background live during the record. Use standard apple airbuds (with built in mic) for the recording, it seems to be a good enough balance by default when recording mic, background music and in-game sounds (with game music turned off). The app I use to record is youtube gaming (https://play.google.com/store/apps/details?id=com.google.android.apps.youtube.gaming&hl=en_GB) it's all very simple and easy to do - I'm planning on releasing a new style of vids soon so keep an eye on the channel!