Rushed out in 1970 as a way to bide time as the Who toiled away on their follow-up to Tommy, Live at Leeds wasn't intended to be the definitive Who live album, and many collectors maintain that the band had better shows available on bootlegs.

But those shows weren't easily available whereas Live at Leeds was, and even if this show may not have been the absolute best, it's so damn close to it that it would be impossible for anybody but aficionados to argue.

Here, the Who sound vicious -- as heavy as Led Zeppelin but twice as volatile -- as they careen through early classics with the confidence of a band that had finally achieved acclaim but had yet to become preoccupied with making art.

In that regard, this recording -- in its many different forms -- may have been perfectly timed in terms of capturing the band at a pivotal moment in its history.

There is certainly no better record of how this band was a volcano of violence on-stage, teetering on the edge of chaos but never blowing apart.

This was most true on the original LP, which was a trim six tracks, three of them covers ("Young Man Blues," "Summertime Blues," "Shakin' All Over") and three originals from the mid-'60s, two of those ("Substitute," "My Generation") vintage parts of their repertory and only "Magic Bus" representing anything resembling a recent original, with none bearing a trace of their mod roots.

This was pure, distilled power, all the better for its brevity; throughout the '70s the album was seen as one of the gold standards in live rock & roll, and certainly it had a fury that no proper Who studio album achieved.

It was also notable as one of the earliest legitimate albums to implicitly acknowledge -- and go head to head with -- the existence of bootleg LPs.

Indeed, its very existence owed something to the efforts of Pete Townshend and company to stymie the bootleggers.

The Who had made extensive recordings of performances along their 1969 tour, with the intention of preparing a live album from that material, but they recognized when it was over that none of them had the time or patience to go through the many dozens of hours of live performances in order to sort out what to use for the proposed album.

According to one account, the band destroyed those tapes in a massive bonfire, so that none of the material would ever surface without permission.

They then decided to go to the other extreme in preparing a live album, scheduling this concert at Leeds University and arranging the taping, determined to do enough that was worthwhile at the one show.

As it turned out, even here they generated an embarrassment of riches -- the band did all of Tommy, as audiences of the time would have expected (and, indeed, demanded), but as the opera was already starting to feel like an albatross hanging around the collective neck of the band (and especially Townshend), they opted to leave out any part of their most famous work apart from a few instrumental strains in one of the jams.

Instead, the original LP was limited to the six tracks named, and that was more than fine as far as anyone cared.

And fans who bought the LP got a package of extra treats for their money.

The album's plain brown sleeve was, itself, a nod and nudge to the bootleggers, resembling the packaging of such early underground LP classics as the Bob Dylan Great White Wonder set and the Rolling Stones concert bootleg Liver Than You'll Ever Be, from the latter group's 1969 tour -- and it was a sign of just how far the Who had come in just two years that they could possibly (and correctly) equate interest in their work as being on a par with Dylan and the Stones.

But Live at Leeds' jacket was a fold-out sleeve with a pocket that contained a package of memorabilia associated with the band, including a really cool poster, copies of early contracts, etc.

It was, along with Tommy, the first truly good job of packaging for this band ever to come from Decca Records; the label even chose to forgo the presence of its rainbow logo, carrying the bootleg pose to the plain label and handwritten song titles, and the note about not correcting the clicks and pops.

At the time, you just bought this as a fan, but looking back 30 or 40 years on, those now seem to be quietly heady days for the band (and for fans who had supported them for years), finally seeing the music world and millions of listeners catch up.