Hey it's NZ music month why not have some local bands.
Arch Hill has a free 10th anniversary album download with all sorts of great bands on it. Under the radar have a whole page of free downloads. And it's the same story at Sellmates.
Plenty of other bands have free downloads on their facebook pages or make mp3's available through radio stations.
Of course you probably won't find any free downloads from bands signed to those greedy, money hungry mainstream labels. But then all the best music is independant.
Could customers use these sites unsupervised? Sure some could but the ones who struggle to use a mouse might find it a bit challenging.