The current popularity of live events broadcast into theaters (like the weekly Metropolitan Opera performances at several local sites) has taken me by surprise. I remember the days when "closed-circuit" events - boxing matches, the Indianapolis 500 and the infamous Evel Knievel canyon jump - were common, but I thought that competition from cable TV and pay-per-view distribution had made that sort of thing extinct.

But before closed circuit and the current digital broadcasts, there was ...Electronovision, an almost forgotten experiment that premiered, peaked and disappeared in little more than a year, 46 years ago. Electronovision was an attempt to get quickly produced recordings of various live performances into theaters, not as live, closed-circuit events but on film, processed rapidly enough to reach theaters while the events were still fresh.

The Electronovision programs were recorded electronically with multiple cameras, much like a TV show (but with higher definition than standard television), edited live, then converted to 35mm film and rushed out to theaters.

The first offering, a Broadway production of "Hamlet" starring Richard Burton, was given a limited engagement of only four screenings, after which all prints (save for one, later found in Burton's home) were destroyed. The third Electronovision production, a biography of Jean Harlow rushed out to beat a more-expensive film version to theaters, proved to be its swan song.

In between Hamlet and Harlow there was a rarely seen but lovingly remembered concert film called "The T.A.M.I Show," billed as the first of a proposed annual series of concerts called "Teenage Awards Music International." The "awards" never materialized, and a second concert film, "The Big TNT Show" - unavailable on DVD, unfortunately - went mostly unnoticed, but "The T.A.M.I. Show" remains a landmark of pop history, offering a wide view of Top Forty music circa 1964, just as the British Invasion was cresting. With its forthcoming release on DVD from Shout Factory on March 23 (and airing on select PBS stations next month), a landmark in pop music history is finally given a new life.

Filmed at Santa Monica Civic Auditorium in October 1964, and given a limited two-day theatrical run a few weeks later (a more traditional release followed, but with the Beach Boys' performance removed for contractual reasons), "The T.A.M.I Show" isn't really much more than a TV variety show - The Ed Sullivan Show" or "The Hollywood Palace" with the plate-spinners, ventriloquists and "grown-up" acts removed.

Some of the performances are awkwardly truncated "greatest hits" medleys, and the nicest thing you can say about the comic chatter of hosts Jan and Dean in between the musical segments is that it's brief. But those are minor flaws compared to the sheer energy of the performances and the scope of the musical acts.

Backed by a band led by Spector protege Jack Nitzsche and featuring many of the best session musicians of the time (look carefully and you'll spot Leon Russell on piano and Glen Campbell on guitar), "The T.A.M.I. Show" pulls together many of the biggest names from the dominant musical trends of the day: Motown (The Supremes, Marvin Gaye and Smokey Robinson), the British Invasion (Gerry and the Pacemakers, Billy J. Kramer and a five-song set from the very raw, pre-"Satisfaction" Rolling Stones), and surf music (The Beach Boys, Jan and Dean), as well as one authentic cult band (the Barbarians, best known for having a drummer whose left hand had been replaced by a hook) and the one-man musical genre that was James Brown.

For many viewers, the highlights of the show will be the two closing acts, Brown and the Stones, the former in full form, dancing, doing splits, and milking every minutes of his traditional faux-stage-collapse in the middle of "Please Please Please." (I'm pretty sure that I had never seen Brown prior to seeing "The T.A.M.I. Show" in 1964 - it's not something you'd easily forget). No argument there, but watching the film recently, I was most impressed by Lesley Gore, all of 17 when the concert was taped and commanding the stage with a powerful voice and surprising self-confidence. Her "You Don't Own Me' is as proud and self-assured a moment as anything the show's more flamboyant performers offer, filtering her other hits - silly songs about teenage romance and rejection ("It's My Party," "Judy's Turn to Cry") - with a genuine sense of defiance.