Prince at First Avenue in 1984 around the time of "Purple Rain's" release. / David Brewster, Star Tribune file

Prince at First Avenue in 1984 around the time of "Purple Rain's" release. / David Brewster, Star Tribune file

If the Smithsonian or Library of Congress or aliens who take over Earth ever want to archive the most important stash of video ever shot in the great state of Minnesota, it should be this: Almost 14 minutes of grainy and slightly warped but otherwise vividly captured and emotionally drenched footage from the Aug. 3, 1983, benefit for the Minnesota Dance Theatre at First Avenue.

The innocuous-sounding concert, of course, was actually the legendary night that Prince debuted and recorded some of the songs that would make up “Purple Rain.” Here you have the title track captured in all its weepy glory.

This occasionally unearthed video -- plastered all over Facebook and elsewhere this week via YouTube as Sunday’s Revolution reunion/benefit concert at First Ave nears – includes detailed and (best we can tell) accurate written commentary about the performance. Maybe the most interesting information it provides is how the audio from this performance was cut up and overdubbed into the final version that would wind up in just about every music lover’s record collection around the world. There's a funny part where you hear a fan's "wooo!" that wound up on the album. Really, though, the clip’s greatness needs no explanation.

Of course, the originator of this particular version of the video remains a mystery. By the time you read this, Prince’s lawyers are probably working to it taken down. Enjoy it while you can.

However long it stays up on YouTube, this footage leaves two lasting impressions: 1) The Revolution’s role in “Purple Rain’s” success has been relatively underrated over the years. You can feel Prince vibing off his band in this case. Perhaps he should think about making another album with them again some day. And 2) That original audio recording of the Aug. 3 concert might be the most amazing live album most of us have never heard, and it's begging to see the light of day. Not that Prince’s recording career could use a boost or anything.

You can read more here about the Revolution's reunion and drummer Bobby Z's return to form. One thing you can't get: a reliable answer to the question of whether or not Prince himself is going to show up Sunday.