ASK Ewen Bremner what he makes of Glasgow-born music supremo, entrepreneur and raconteur Alan McGee, the man he plays in the new film Creation Stories, and the actor could easily reply which Alan do you mean?

"I think there are various stages of Alan," he suggests down the line from New York.

"There's the spunky kid who has a passionate need to be out in the world and be part of something important and lay claim to his position in that stratosphere of music back in the 1980s."

Then, he adds, there was McGee the unlikely businessman. "As a business prospect, on paper, he looks like a disaster. But he's the opposite. He's been hugely successful.

"He doesn't do anything the way you're supposed to. And all of the bands he works with are absolute liabilities. Nobody would touch because they were so explosive. They were always breaking into fights.

"He had an appetite for that kind of energy where a fight could break out any minute or gold could be found."

You can find both of those different versions of McGee in Creation Stories, and a few more. There's also McGee the chancer, McGee the talent scout (you know I'm going to mention him discovering Oasis at this point, don't you?), McGee the hedonist, McGee the addict and McGee the ex-addict.

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Alan McGee. Photograph Robert Perry

Today, Bremner is doing a day of press for the film. Journalists are stacking up like planes. I hear the tail-end of the interview before me and the next journalist pops onto the line just as I ask my final question.

Bremner, who for most of us will forever be Spud in Trainspotting, makes a very decent McGee (or McGees to continue the idea we started with) in Creation Stories to be fair, even if, as he was born at the start of the 1970s, some might say he is a little old for a role in which he has to play a man in his twenties. (And we won't even mention the fact that he's from Edinburgh.)

Creation Stories is a movie that's as much myth as memoir. With a script by Irvine Welsh and Dean Cavanagh, it's perhaps inevitable that to a large extent it takes the legend and runs with it.

"It was not a documentary we were setting out to make," Bremner points out. "We were trying to make something that is high-octane entertainment, that's funny, dark and mad."

The result is, at times, cartoony. But it's also willing to show the vulnerability of the man behind the myth, Bremner suggests.

"I think the world of Irvine Welsh's writing allows for all of that to be contained; for stuff that is really cartoon-like and outlandish and at the limits of ridiculousness, coupled with the real gravity of the human condition and the limits of our ability to function socially and to be a loving person and to survive adversity, whether that's poverty or violence or heartbreak or whatever."

Read More: Alan McGee - "I've changed. I've got rid of everything."

Read More: Ewen Bremner on life after Trainspotting

Directed by Nick Moran operating under the usual no-time, no-budget exigencies of British cinema ("It was absolutely kick, bollock and scramble," Bremner admits), Creation Stories is a pop culture movie; a movie that takes in indie music, the birth of rave and Britpop and travels from the riots at early Jesus and Mary Chain gigs to McGee's chance visit to King Tut's in Glasgow where he saw Oasis for the first time.

To its credit, it's a film that is as interested in The Television Personalities and My Bloody Valentine as it is in the Gallagher brothers.

And it is, like every other historical film, from time to time, something of a wig movie.

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Jason Isaacs and Ewen Bremner in Creation Stories

The question is, what does it tell us about the man it is based on? Perhaps the key line in the movie is "modesty gets you nowhere," and you could never accuse McGee (who in real life is wonderful company, by the way) of hiding his light under a bushel (or a member of The Bodines for that matter).

"I think he had nothing to lose," suggests Bremner.

He certainly had nothing to start with. Growing up in Glasgow, McGee was browbeaten and sometimes just beaten by his dad (played in the film by Richard Jobson).

"That's the other thing that he makes clear in his autobiography and the film," Bremner points out. "He wasn't going to live scared, to live in fear. Growing up, he had to make that choice; if he was going to live in fear or if he was going to stand up to his fears and overcome his perceived limitations of his upbringing. 'I don't need to be humble. I don't need to be modest. I don't need to play by the rules.'"

Having spoken to McGee at the time he published his memoir back in 2013, I wonder, though, if the film doesn't slightly soft-pedal the relationship between McGee and his father?

The real relationship of father and son was marked by violence. His father beat him, sometimes brutally. When we spoke in 2013, McGee suggested that this form of "tough love" gave him fuel to go out in the world and get ahead.

"There's no doubt about it, it was a tough time he was growing up in," Bremner agrees. "It was a tough world that he was growing up in, and there were forces that were oppressive and he needed to protect himself from.

"I think through his life he's gone through a lot of wrestling with his relationship with his father and I think it's gone through various revolutions. There were times when he had to close off from his dad and there were times when he was full of love for him and really reconnected with him. I think that cycle went on more than a couple of times. So, I think it's something that drove him in some ways and that comes over in the film. But, at the same time, he's got the scars.

"And who knows?" he continues. "I don't feel like I know exactly what happened … Domestic violence is a bigger conversation than I think we have time for just now. I absolutely don't want to say anything flippant about that."

The appeal of Creation Stories is the sense that you are being told the inside story. (Whether you believe it or not is up to you). Given his track record from Trainspotting to Wonder Woman, it's no great surprise that Bremner-as-McGee is its greatest asset. And yet, he admits, when it comes to Creation, both music and myth, he is very much an outsider.

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Ewen Bremner in T2 Trainspotting

"I don't think I had any Creation records. I was never really into indie music or rock music, so I didn't pay attention. And I wasn't really into acid house, so I missed that whole cultural moment. Or all of those cultural moments. I didn't know a hell of a lot about it."

What was he listening to in the 1980s and 1990s then? "I was listening to a lot of old American soul music, African pop music some European folk music. Rock and indie didn't do it for me, and acid house didn't do it for me. It just didn't go in.

"There are certain things that I'm supposed to be into as a Scottish person. I'm hopeless. I can't make head or tail of football. It just does not compute at all.

"But I was really excited that Alan was the guy who signed Ivor Cutler and signed Kevin Rowland. These guys are real Gods. He's definitely got taste."

It's time to go. Time for that final question. What, I ask Bremner, is his favourite Alan McGee story?

"I do enjoy the magic stuff," he says. "There are some really good stories about him going through a very strong magic phase where he was travelling first class with his case of magic wands that belonged to famous sorcerers through history. It's fascinating that he sees himself as part of that tradition. I think if that exists, he absolutely is part of that tradition of sorcerers."

There you go. Who does Ewen Bremner think Alan McGee is? A magician.

Creation Stories screens as part of the Glasgow Film Festival from next Saturday. Visit glasgowfilm.org/glasgow-film-festival for details. Creation Stories will be available on Sky Cinema from March 20