"Who's this?" asks a bemused looking American chap.
"It's Liam Finn. Neil's son," I explain. He gives the thumbs up and carries on watching as a solo Liam makes a racket and throws himself around the stage of Los Angeles indie-rock club, Spaceland.
A couple of minutes later, the American leans over again, shaking his head in delighted disbelief: "He's crazy." And he's right.
However, Liam Finn's one-man show is not solely rock 'n' roll chaos. During the set he morphs from a serene singer/songwriter on one song, to a mad professor in his musical laboratory on another, and a wild and woolly animal on others.
After two albums and migrating to Britain, Liam's band, betchadupa, are on a "hiatus". So, as well as being part of the reformed Crowded House live line-up - "Liam can play my acoustic guitar parts better than I can because he's younger, funkier and got a better beard," says his father - the London-based musician is touring the world as a one-man band.
He sings, plays drums and guitar, does odd things with a theremin (an early electronic instrument), and uses a loop pedal to keep the different instrumental parts going throughout the song.
On his debut solo album, I'll Be Lightning he does the lot, too: writing, recording, producing and playing nearly all the instruments.
In the audience tonight are a sprinkling of LA locals, reps from three American labels who are "keen on the record", and a few friendly faces from home - including Auckland band the Mint Chicks who have just finished an American tour.
Some songs are mad, some beautiful, and some sad. On the maudlin Gather To the Chapel Finn simply strums his guitar and sings; on Lead Balloon he belts the song to an end and falls backwards off the drum stool. He regains his feet, takes a few deep breaths, and composes himself for Lullaby.
The show is seat-of-your-pants stuff and a logistical challenge. It looks like a hell of a lot of fun. But what brought this on? Why, just as Neil has reformed his chart-topping band, has the younger Finn decided to go out under his own world-famous-in-New Zealand name?
The day after the show, Liam lounges on a recliner by the pool at the Sunset Marquis in Los Angeles. He looks fresh and happy but his bright red vodka drink is the hair of the dog.
After last night's gig he and the Mint Chicks commandeered a room and got on it. They couldn't have chosen a more appropriate place. This hotel, located just off Sunset Boulevard, attracts some famous guests, including the Rolling Stones, Iggy Pop, KISS and the Kings Of Leon, as well as many A-list actors. Its corridors and walls have seen some sights.
"Rock star to your left. Famous actress to your right. You're either at the Sunset Marquis or at a treatment center," is one of the hotel's slogans.
An ice cube's throw from where Liam sits is where Whitney Houston used to hang out by the pool. And up there in one of those rooms behind him is where Dave Gahan from Depeche Mode overdosed a few years back.
Liam Finn, on the other hand, doesn't really look like a rock star. He just looks like a young guy with a very manly beard. Although, if last night is anything to go by, he knows how to put on a rock 'n' roll show.
"It's really stimulating as a musician, but at the end of the day you've got to have a few songs in the midst of it, otherwise people will get a bit sick of the indulgence ..." he says with a smile.
"It is quite indulgent, really. I'm up there just buzzing myself out and enjoying it, but I think that because I'm having a good time, people respond to it. And it's not pretentious in any way because my soul is being bared and it could **** out at any moment," he laughs.
After doing his one-man show in London over the past six months, Liam has noticed how people find it refreshing to see someone playing music solo on stage, rather than a band.
"It isn't a rehearsed thing but I think sometimes the more disastrous it gets, the more I'm pushed to make it work. It's quite satisfying to do - but it's also incredibly dangerous. And I like danger."
For a 23-year-old, he's already done more in a musical sense than most musicians could dream of. Among other things, he's played with a few of his idols, including Pearl Jam's Eddie Vedder, Johnny Marr from the Smiths and Radiohead's Phil Selway and Ed O'Brien as part of his father's Seven Worlds Collide concerts in 2001.
He's also released two albums and a handful of EPs with betchadupa, and most recently played with Crowded House at their first big reunion gig at the Coachella Festival in Palm Springs, California.
Yes, it certainly helps having a family name like Finn. But he doesn't rely on it. During my first interview with him in 2002, around the time betchadupa were releasing their debut, The Alphabetchadupa, he made it clear he and the band didn't want to get by on a name. He even referred to it as "the last-name scenario".
His attitude is much the same today.
"It's always going to be a point of interest but it's not something that worries me and I can't rebel against it. I'm proud to be a Finn."
When he started the one-man band, he called himself Lester Osbourne - his "porn name" - for a while. "But the record is so me that it seemed like an obvious thing to use my own name."
He's the elder of Neil and Sharon Finn's two sons. As a toddler he was living a rock 'n' roll life on the road with his dad and Crowded House. Neil recently found some old footage recorded on the Crowded House tour van during the band's first jaunt through America.
The Paul Kelly song Before Too Long was playing on the stereo, Liam was sitting on bass player Nick Seymour's knee, and drummer Paul Hester who died in 2005, is dancing around the van.
"Nick was singing Before Too Long to Liam and it's an amazing bit of footage really," says Neil. "It's incredible to think that Liam spent his first few years pretty much touring constantly with Crowded House. And it's amazing, I look at him now and he's got this really good beard - a beard I could only dream of - and he's also made an absolutely brilliant record. It blows me away." The Finn musical gene runs deep.
Neil recalls how at Coachella, Liam took over lead vocals on Don't Dream It's Over when a rogue fan of headlining act, Rage Against the Machine, threw a bottle and knocked Neil's microphone off its stand.
"[It was] the great thing about having your son on stage with you," says Neil. "I didn't realise this at the time, and I kind of thought there was this little guardian angel out there, because I could still hear my voice. Liam had immediately leapt forward to his microphone and started singing the song."
At times on I'll Be Lightning, and on the harmonies he contributes to the new Crowded House album, Time On Earth, he sounds more like his uncle Tim than his father.
But if there's one thing Liam has inherited most strongly from Neil it's the love of a good melody.
"I grew up with a lot of melody around and I don't think I could fight it," says Liam."It's what comes naturally and that is, I think, what maybe made this album lend itself to not being a rock band album.
"I mean, I love to scream and go wild, but I don't want to be forced to do that. The melodies are the stuff that come naturally and they're the songs I feel most proud of."
Much of his solo album is inspired by experiences of the past three years, including when betchadupa moved to Melbourne, and then London; a relationship break-up; and seeing "the band go through the mill".
"It's all kinds of other experiences - a few highs and lows - I think all that just naturally came out in these songs," he says.
Liam and his betchadupa bandmates left school to play rock 'n' roll for a living - and for a while it was all going reasonably smoothly.
When they moved to London in 2005, the only New Zealand act living in Britain were the Datsuns. But that first year, when the band were holed up in west London, was the hardest of their life. They had guns and knives pulled on them and a computer containing demo recordings was stolen.
"We were at the stage of just having to start again and it was humbling, very humbling. London's a tough place to live in general and to be in a band and make a living is even harder."
Then they moved to East London - "which is really arty and has a real vibe to it. There's more young people and a better mix of people" - and by this time other New Zealand bands like Connan and the Mockasins, the Checks, and James Milne (aka Lawrence Arabia from the Reduction Agents) had moved to town.
But after 10 years as a band, betchadupa decided they needed a break. "It's like a relationship where you reach a point where things are really good, and you still really love each other, but you maybe lost a little bit of your own identity in the process," says Liam. "We were four guys who had grown up together since we were 11 and we started the band soon after. We needed to go and fend for ourselves and figure out who we were on our own. I think we're all a lot happier now.
"And living together as well - it was so intense. But now when we hang out it's fun and everyone's funny and it's like, 'That's right, you're a funny ****. You really appreciate one another."
And musically, songs like Remember When and At the Chapel from I'll Be Lightning are intensely personal. Liam admits to feeling a little self-conscious about asking his best mates to play them.
"For me, I definitely felt I needed to fulfil something and not compromise songs that are possibly the most intimate and genuine songs I've ever written. But also I didn't want to have to compromise the way I heard them in my head." He's an eloquent and smart talker.
Although there's probably a little bit of the control freak in him, he's humble and open. It's understandable he felt awkward playing these songs to his mates but he also felt pangs of self-consciousness at the notion of sharing his feelings and thoughts with the world.
"But eventually I thought, '**** it. This is me and I'm proud of saying these things'.
"I learned to go with my gut feeling and not be worried or self-conscious. I think the only thing that makes the good and the crap different in this world is honesty.
"Like watching the D4 play Party, you totally believe them - which is just as valid as Elliot Smith singing a song about how unhappy he is. Some of [my] songs are melancholic and sad, but they're also just very real and not bitter or angry."
Now, Liam and James Milne live in the same house together in London and he describes it as a "sort of weird Velvet Underground/Andy Warhol collective scene.
"I've been writing songs with James, and living with him is a good thing because we'll come home and it's like, 'I wrote a song, bro'. 'Play it. Play it'. Then I go, 'Oh yeah, I've written a song too'. It's really good because you're pushing each other.
"Everyone's on a cool mission of their own and it's really inspiring. And we're all collaborating. It definitely feels like there's something happening and we're going to be able to really utilise each other."
The title track of Finn's album was co-written by Connan Hosford (of the Mockasins) and Finn says it was "one of the most joyous thing' he's written.
"We recorded it late one night when we were all drunk, with Dad playing bass and Matt [Eccles, from betchadupa] on drums. It felt like Neil Young and Crazy Horse.' When he plays live, however, he doesn't need a Crazy Horse behind him. Give him a loop pedal and he's mad enough.
The inspiration for forming a one-man band came from seeing musician and producer Jon Brion, who has composed soundtracks for movies such as The Eternal Sunshine of a Spotless Mind, Punch Drunk Love and Magnolia, play at Largo in Los Angeles.
"He's the most amazing musician and he does that kind of looping thing. He'd play drums for a minute and a half, and then he'd hit a button and the drums keep going. Then all of the sudden he'd be playing the bass line, and then the guitar line, all over it. He's really pushing himself to nail it. And that's what I love about it.
"I'm here to be an entertainer," says Liam, "and I'm going to throw myself around on stage. I'm also going to think about what I'm singing about and be as true to the song as I can."
- Canvas, NZHERALD