GORDON McPherson should be among Scotland's best-known composers. If he isn't, then, admits the Dundonian whose latest orchestral composition, The New Black, will be premiered on Saturday by the BBC SSO, it's probably his own fault.

Many people on the music scene simply have little idea who he is, or of the style and extent of his repertoire. Since 1986, the individualist composer has produced close on 100 compositions. Most of them are played. None gathers dust on a library shelf.

His recent works include Bloodshake, a concerto for three flutes; Descent, an opera about a character who becomes trapped in an internet porn chat-room and discovers that he has logged on to hell; and Ghosts, an hour-long suite of pieces for orchestra, film and tape (yet to be premiered), which is McPherson's investigation and explanation of the paranormal.

So, with his first BBC commission, The New Black, which promises to be a violently energetic piece - he describes it as "like a big fridge coming straight at you" - about to go into rehearsal, why does Scotland not know more about Gordon McPherson? Is he retiring, withdrawn or enigmatic?

Quite the reverse. When he first appeared on the scene about 20 years ago, many people felt uncomfortable with the outspoken Dundonian's views. He seemed aggressive, hard-edged, uncompromising and a little scary. He belonged to no clique and toed no party line.

In fact, however, he's not aggressive, just plain-speaking and forthright in his views. As far as his music was concerned, he wasn't interested in the public relations machine. He neither courted nor sought publicity. He just got on with the writing and, frankly, didn't botherwith the whole business of previews, reviews, interviews, recordings or the wider dissemination of his music. Bluntly, important pieces came off the page and on to the stage, and nobody knew because McPherson hadn't bothered to tell them.

Two decades on and, as head of the thriving composition department at the RSAMD, McPherson is now 40 and a pillar of the musical and educational establishments.

So he'll have mellowed, right? Like hell he has. Young composers signing up for his bustling, vibrant department are immediately exposed to the McPherson philosophy of modern classical music, which runs as follows, verbatim: "There's a problem with contemporary music: there's no audience for it, naebody's interested and 99.9per cent of it is rubbish.

"There's nothing wrong with that, but the starting point is that you don't come in here thinking it's a noble profession because it's classical music, and, therefore, everybody will be interested in what you're doing. Nobody's interested in what we're doing. It doesn't work like that. You have to make them interested, and just because you can write a string quartet, doesn't mean that you're somebody special. Just finish it, get on with the next piece, and if you're half lucky you might end up with a string quartet that becomes part of the canon.

"The bottom line is that the students all know that what they're doing is not a cure for smallpox; it's just another piece. And that gives them the freedom to express themselves without feeling precious about what they're doing."

McPherson's is the hard-knocks school of composition. But its purpose is "to keep the students' feet on the ground and, creatively, their heads in the clouds". It must be working, because in a department where there were around three firststudy composers when McPherson took over in 1999, there are now 30 composers at undergraduate and postgraduate level, all producing music that is being played (and some of it very impressive indeed). Further, there are around 20 applicants for only two or three places next session. "We're now in a position where we can pick the best."

Meanwhile, McPherson has applied the hard-knocks rule to himself, and has undergone something of a sea-change in his attitude towards his own music.

"It has been in my own nature to shut up and get on with the writing, " he says. "Maybe it's an east-coast, Calvinist thing. I genuinely think there is a part of the north-east mentality that says you don't shout about yourself and what you do. We're not as gallus as the west coast people, and it's work, after all. You just get on with it."

But some recent euphoric responses to his music by fellow composers set him thinking. "Maybe it's time I did start to tell people what I'm doing; it does seem that more people are beginning to get it, and to get what I'm trying to do."

But giving himself a hard knock doesn't merely apply to his attitude.

It's clearly affecting his music, and the way he writes it.

The New Black, with a different title, was under way, and McPherson wasn't happy with it - not a condition with which he is familiar. So he started it again, and was still unhappy. He had a third attempt, and was still dissatisfied.

Then, listening to his car radio, he was blown out of his seat by the music of New York rock band Yeah Yeah Yeahs. "It was completely raw, lo-fi, gritty and it hit me what was wrong with my piece. It was too refined. It was too 'orchestral'. It was just another piece for orchestra." Ruthlessly, he ditched it wholesale, started again, retitled it and produced The New Black, which came out "very fast, very loud, black with notes from beginning to end and a big, loud mental scream, like a raw expression of joy and excitement".

It is, he says, "written in a way that hopefully will encourage the musicians to get stuck in and enjoy it".

His one concern is the unremitting length and loudness of the 20minute piece. "After all, embouchures are embouchures, " he says with a grin that is equal parts challenge and mischief.

The New Black (along with music by Steve Reich and Tansy Davies): BBC SSO, City Hall, Glasgow, Saturday, 9pm.