Longer ‘Woodstock’ Still Prime Viewing : Movie review: The 25th-anniversary director’s cut includes 44 minutes of previously unseen footage.

The reissue of the Oscar-winning documentary “Woodstock” (at Mann’s Chinese Theater and South Coast Plaza in Orange County) in a 25th-anniversary director’s cut is vital, if it serves only as a utopian corrective--in advance--for August’s inevitably cynicism-inspiring Woodstock ’94 festival.

A new generation can now marvel at the sight of the original fest’s hippie promoters grinning goofily as they announced they’d lose millions by letting the advancing hordes in for nothing. It was the last great gasp of free love and free admission; expect this August’s cash cow at Yasgur’s farm to be fortified by something a little sturdier than wire mesh.

Director Michael Wadleigh has fortified his “Woodstock” by adding 44 minutes of previously unseen footage to his already three-hour-plus document. It’s either a measure of how well cut this is or how dreadful a lot of this summer’s new two- and three-hour dramas are, but it actually doesn’t seem that unbearably long, even when Wadleigh starts the second half with restored outtakes of the less-than-prime Jefferson Airplane.

Now, as ever, “Woodstock” is not just a great slice-of-time documentary but still the ultimate rock concert movie: A quarter-century of advances hasn’t brought about any real improvements on the multiple-camera filming techniques or even significantly dated the split-screen effects and varying aspect ratio tricks. The advent of digital sound, on the other hand, has given the remixed soundtrack a theatrical glory unknown a generation ago. At this pristine volume, Jimi Hendrix’s concluding bit may not be quite suitable for anyone with a heart condition, which would constitute more of the Woodstock nation than some of us might like to consider.

“Woodstock” may be a slightly better film for being longer, but it’s the familiar material that’s the best reason to go back: Pete Townshend’s windmill guitar strums. The nun flashing the peace sign. The gentle “brown acid” stage caveats, by now as familiar--and misquoted--a part of movie lingo as “Play it again, Sam.”

As for the new stuff, you get a good deal more documentary footage, a little more of Hendrix, Canned Heat and the Airplane, and Janis Joplin as part of the film for the very first time, with “Work Me, Lord” a very good if not quite defining performance.

The most notable musical addition is the insertion into the standing Hendrix footage of “Voodoo Chile,” shot on the last day as most of the weather-beaten crowd had already started slouching back to civilization. It’s a measure of how powerful a document of a faded dream Wadleigh’s “Woodstock” is that the anticlimactic shots of the emptying, litter-filled fields laid under Hendrix’s scorching notes make you feel intractably and unexpectedly sad that they, or we, ever had to go home.