The idea that MySpace Music is fighting an uphill battle to establish itself as a social-network music service isn’t particularly interesting to me.

But this one aspect of their long-term approach is:

Eventually, [MySpace Music director Courtney] Holt wants to build up discussions of artists’ discographies on MySpace and foster “social DJs” — playlist creators who are as influential as radio disc jockeys once were.

Custom-rolled playlists that followers would use to get clued in on new music they might otherwise never have found. That’s what old-time radio DJs did back in the day, and since this fits into the trust factor that social networks foster, it’s a natural. It’s funny to imagine the growth of an online cognoscenti of music taste-makers who’ll have a direct and measurable impact on which song is a hit and which isn’t. In turn, these social DJs would gain a fair measure of fame themselves, leading to crossover success in other media.

That’s all if MySpace’s grand plan comes off. But even if it doesn’t, I can see this idea of the playlist-based social DJing catching on elsewhere, filling the void between major-label marketing and music-listener consumption.