Emmett Malloy’s exuberantly entertaining Big Easy Express — an infectiously joyful account of a 2011 whistle-stop tour by the indie folk ensembles Mumford & Sons, Old Crow Medicine Show and Edward Sharpe and the Magnetic Zeros — has been available on DVD, Blu-Ray and iTunes for the past several weeks. But, trust me, you don’t want to see this good-time flick for the first time on any of those platforms.

No, what you really want to do is see it the way God — and Malloy — intended you see it: On a big screen. With a lot of people. Where there’s plenty of room to spontaneously clap your hands, sway in your seat and maybe, just maybe, dance in the aisles.

A place like Austin’s Paramount Theatre, where I fell in love with the movie last spring on closing night of the SXSW Festival. Or a place like… like… well, gee, I don’t know, maybe a place like 14 Pews, where they’ll be hosting the H-Town premiere of Big Easy Express this week at 7 p.m. Wednesday and Monday, and 4 p.m. Sunday.

Malloy, who also directed the acclaimed White Stripes documentary Under Great Northern Lights, went along for the ride to record the music, merriment and misadventures when the three bands banded together aboard a 14-car train for a six-city, Oakland to New Orleans tour. Judging from his film, there was a minimum of drama on board – the groups evidently formed a mutual admiration society while jamming together until the wee small hours during their cross-country journey – and an abundance of high spirits during each performance at every stop.

Indeed, Magnetic Zeros lead singer Alex Ebert occasionally appears possessed by Pentecostal fervor as he hops about barefoot on stage during songs, to the delight of cheering crowds. And during a stay-over in Austin, Mumford & Sons shake the rafters while performing their hit “The Cave” with a little help from the Austin High School marching band.

Right from the start, Malloy lets you know you’re in for a good time with a breezily cheery credits sequence that follows the lithe and lovely Magnetic Zeros singer Jade Castrinos as she drifts – no, make that dances – from car to car aboard the train, introducing the audiences to each of the bands.

It’s a scene that’s nothing short of delightful. And according to Malloy, it very nearly didn’t happen.

CultureMap: There’s something almost intoxicating about your opening scene. It seems totally spontaneous and unplanned. But, of course, nothing’s ever that simple, right?

Emmett Malloy: That was actually kind of the biggest learning curve for me while making this film. Because we were really restricted by the rules and regulations of the railroad. It was like, we could never really plan anything, because we never knew for sure when the train was going to stop, or when we could get off and on.

So even though I had all these ideas conceptually in mind for the film in general, most of them went out the window when I realized how difficult it was to co-ordinate three bands, and figure out just when we could get off the train.

CM: So how did you make the magic happen?

EM: That opening shot, it was just something I got the idea to do because I thought it would be a great way to kick things off. But, you know, these weren’t small bands. These were bands with a lot of moving parts, so to speak. So we only got one opportunity to do it.

We had all three bands, each in their respective cars, and we got it all organized on the morning we were heading into Austin. Everybody agreed and liked the idea. But there was no way for us to communicate with one another between cars. We had no walkie-talkies or anything. So when you went from one car to the next, you might as well have been going to the other side of the world.

We decided to have Jade move along because she was one of the few females in the movie, and we felt she would give that opening shot a different spirit. So we set everything up, and ran up and down the cars to let everybody know we were about to begin. We didn’t have any special rigs or anything. It was just me and the cameraman – me holding his shoulders and getting the doors for him while we were moving along.

And we got about midway through Mumford & Sons’ car – and then the train stopped.

CM: Oh, no.

EM: Yeah, and everybody said, “C’mon, let’s just keep doing it.” But I felt the shot just didn’t work that way, because the train wasn’t moving. It wasn’t interesting to me – it didn’t feel like we were going anywhere. It looked like we were on a studio set or something. So I just kind of threw in the towel, and said that was a good try, but we’d figure out a different idea for this opening. So all the bands started to scatter a little.

And then the train started moving again.

CM: Well, of course.

EM: So I started running like a bat out of hell up and down the train again, trying to get everybody back in their spots. And I have to say, some of them were a bit reluctant, and saying things like, “Oh, why don’t we just go ahead and get breakfast or something?” But finally, everybody decided to give it just one more shot.

And literally, everybody had to just anticipate us coming, because once I yelled “Action,” I had to kind of just let things be and take them as they were while we were moving. So that’s what we did. We just bounced around and followed Jade.

CM: Do you wish you’d had another take? Or are you wholly satisfied with what you got?

EM: There are some things, some minor things, that I didn’t like, that bothered me. Nobody else would notice them, but I do.

But once I got the credits placed over the scene, I realized that it would work, that it would really grab the audience. And that it was a cool way to introduce the audience to the cast of characters that are going to be stars of this journey ahead.