AUSTIN – At one point in “¡Cuatro!” – one of two Green Day films to premiere at South By Southwest -- Billie Joe Armstrong and his band are complaining about fans that request their oldest songs at their surprise, small gigs. These tiny 2012 concerts were arranged to workshop Green Day’s new tunes live, and with the abundance of material written for the recent “¡Uno!,” “¡Dos!” and “¡Tré!” trilogy albums, they wanted to play the new stuff and not the old.

The rock band referred to older tunes like “Basket Case” as “sacred cows.” “I think cows should be eaten,” Armstrong said in the film.
 
Fast-forward to Green Day’s high-profile SXSW show at the ACL theater in Austin, on a busy Friday night, and only eight songs of the 25 on the setlist were new tracks. There they were, jamming through "Dookie" tunes and crowd-pleasing medleys (yes, plural) of well-trod covers like “Highway to Hell” with “Sweet Child O’ Mine” and “Shout” with “Hey Jude” and “Stand By Me.” On the latter, they were cornballing, shilling, a seemingly cheap move if it didn’t seem like they were having so much fun, and didn’t sound so damn good.
 
Delicious, delicious cows.
 
That’s one of many reasons that makes a film like “¡Cuatro!” so unique: it's a snapshot into the band’s creative process at a given time, when old and covers material has less (or no) bearing on their output to come. When they played “Longview” on the stage at ACL, perhaps those feelings of resentment had dissolved and they again love to play the hits again. Maybe they turned anything negative about "Burnout" and its ilk into positive energy, displacing it onto their audience or industry-heavy attendees. Or some things are just bound to change when you play to an audience of 120 versus 2,000 versus 50,000.
 
Last year, Smashing Pumpkins’ Billy Corgan had some strong words about playing his old hits: “If that audience is there only to see the past, get me off the stage… We have to break a spell with our audience, to get out of the idea that the band from 2008-on was going to be an oldies act,” he told me. “Smashing Pumpkins will never, ever, ever be an oldies act, and if that means the end of the business or whatever, tough sh*t for me.”
 
It’s not “tough sh*t” for Green Day, and revitalizing their old material comes easy. For example, they helped reanimate material from “American Idiot” into a stage musical of the same name. In Doug Hamilton’s film “Broadway Idiot” (also at SXSW) Armstrong’s amazement in hearing “American Idiot” songs in this way transformed him from an idle participant member to a performing cast member. You could see something new click from inside of him, and he ultimately played 50 dates on Broadway as St. Jimmy.
 
“Audiences are going to be on Billie’s shoulder as he goes through that process,” Hamilton told me on the red carpet to “Broadway Idiot.” He said that, a day after it was revealed that Armstrong was going to dip into stage musicals again: the singer will be writing new music for the Yale Repertory Theater’s “These Paper Bullets,” an adaptation of Shakespeare’s “Much Ado About Nothing, ” for a March 2014 premiere.
 
What audiences won’t see from Armstrong’s shoulder is his public meltdown from the stage of iHeartRadio in 2012, which propelled him to check-in to rehab for prescription drug and alcohol abuse.
 
“¡Cuatro!” was completed and locked long before that descent and there’s no inkling of his detrimental addiction, no foreshadowing of the rehab to come. Instead, there’s a snapshot of the band’s drug-use as a lifestyle, with hazy footage of pills being popped and dancing in trashed hotel rooms. Armstrong recalls the first time he and bandmate Mike Dirnt dropped acid; Tré Cool jokes about listening to a new track on shrooms.
 
Again, the health of a band like Green Day is by no means a permanent. “¡Cuatro!” was truly a record of record-making, a place and time and age of the band during the creative process.
 
“They just wanted to do something fun, spontaneous, true to what was going on… Capture that moment in time,” said director Tim Wheeler during the Q&A after the screening. For the references to drug use, “They really stand by this moment in their career in documenting that. I don’t think it shows it in a bad way.”
 
Despite their awesome live show and these adaptable, wild new albums ,“this” moment will be referred to as “post-rehab Green Day,” for better and for worse. As Armstrong said in “Cuatro,” Green Day wants his audience to “grow with you and grow up with you.” Old hits and waning addiction may be in the past, but it’s still consequently a part of who this band is today. With so much great showmanship and joy as seen on stage and in “Cuatro” and "Broadway Idiot," I hope Green Day growing up is for the best.