If Christian McNeill is happier now than he’s ever been, then what was he feeling when he was 20 years old in Derry, Ireland, touring with the band Schtum, with U2 offering the services of their accountant, lawyer and booking agent and a record deal with Columbia Records?

“All I wanted to do was play guitar. All any 20-year-old wants to do is play music and meet chicks. And maybe score some reefer. That was my motivation. It was just to play guitar,” he says on the phone, laughing during an interview from his Boston home. “I had some naïve notion of what ‘making it’ was all about. Then suddenly you’re jumping through hoops for these people who have degrees in accountancy and they’re making creative decisions on your behalf. ... I think Joni Mitchell said it—you need to be young, really good looking and have a willingness to cooperate.”

McNeill didn’t cooperate. At 24, he ditched his band (and his contract) and emigrated to America, disembarking the plane at Logan with $400 and a guitar. That was before he hooked up with Orchestra Morphine when the band toured after the death Mark Sandman. When McNeill arrived in Boston, he created a band called Hybrasil (named for an old Celtic legend), and he wrote and he played, keeping at his music even in relative obscurity.

McNeill’s arrangements build on solid rhythms with an energy that’s closer to an orchestra than to a contemporary indie aesthetic, and his vocals are as powerful an instrument as his guitar. The songs can be folky, jazzy or rock, and they’re almost always danceable. But he still struggles to define his music or to name influences. There are the bands that he loved when he was young—Fugazi, Lou Reed, Television, The Beatles, Van Morrison, Tom Waits, Iggy Pop—and there are the band names he reads off his CD shelf during our interview, where he’s got Morphine, Herbie Hancock, Pell Mell and The The alongside electronica and drum and bass CDs. “I met David Byrne one time in New York when I had this (Schtum) song on the radio, “Skydiver.” He said, ‘Your music is machine-like and singularly unique.’ I said, ‘What?’”

“My earliest memories were having these incredibly complex songs in my head, I’m talking as a 2- or 3-year-old, that would be in my head all the time. It’s probably like a mental illness in a way. I’m not being funny by saying that. I’ve had music in my head every day from when I first remember,” he says.
“The only other way I can explain it is that to me, it’s simple. There are only a finite number of notes. As a great musician in my hometown used to say, he said to me, ‘There’s 12 notes, Christian, pick one.’ I always thought that was a beautiful and simple way to look at music. I hear horn parts, I hear rhythm, I hear full band arrangements in my head, and I’ve always written like that.”

By way of illustration, he describes the signature trumpet that unexpectedly soars like a bird through the middle of the knockout six-and-a-half-minute “The Kicker,” the title track off Hybrasil’s second album (Lunch Records, 2001).

“I walked around with that in my head for two years before I recorded it. I wrote that song in three parts. I had the first part of the song and I had the latter part of the song, and I didn’t know how to piece the two together. ...  People would be talking to me and I wouldn’t hear them because I’d be hearing the trumpet and trying to resolve that.”

To be like that, he notes, “either you’re a self–obsessed jerk or you really are good at music. I’m a textbook narcissist. That’s probably my life story. But that’s what I do, that’s what my role is here while I occupy this body. Not to be a hippie about it, but I really strongly believe that.”

McNeill has written more than 30 new songs in the last year, which he’ll be bringing to The Barley Pub on Saturday, March 18 at 9 p.m., along with the other 500 songs he’s got locked in his head from the last 15 years. He’ll bring Benny Benson on drums and bassist Mike Miksis (of The Resonance). The trio will be opening for the Seacoast’s own Shagbark.

Since he turned 30 years old three years ago, around the time that Hybrasil split up, McNeill has found himself in a new creative phase.

Gone is the sarcasm of albums like “Friendly Destroyer,” with tracks like “Massive Breeder” and “AIDS, Poverty, War, The Fake Economy and Sports.” Gone is the negativity he adopted growing up amid the violence of Northern Ireland, which he’d been channeling through his music.

“I’ve had the most creative period of being comfortable in my skin. The lyrics aren’t contrived, they feel just me. I’m happy performing. (Now) it’s humbler, more human, simpler, and I think it’s better. I want to write something positive. … I’ve got different song titles that are purer, there’s no cynicism at all, I realized I don’t need that.”

And gone is the ego that “can absolutely control you in your 20s,” he says.

“We all struggle with it, and I guess the great thing about it for me was resolving it and saying I don’t have anything to prove. I guess that’s the Zen behind it: when you absolutely give up, that’s when you totally succeed. (When I said) I don’t care about all the stupid things around the music business—the lawyers, the record labels, the booking agents—once I let all those things go, I became so much happier. I became a much better human being to play music with. Absolutely. I think that’s strength and maturity, that a person can admit that. That shows that I really have let my guard down in that sense, I can turn around and say I was a jerk back then.

“But I’m still a good-hearted jerk.”