Martin Suckling is preparing a lecture on Schoenberg's Pierrot Lunaire when I ring him at home in Manchester.

As well as being the most talented composer to come out of Glasgow in recent generations, 31-year-old Suckling is something of an academic whizz kid: top of his class at Cambridge and King's College London, fellowship at Yale, doctoral research at the Royal Academy of Music. He was recently appointed a lecturer at the University of York and says the teaching does him good. "Students force me to stay on my toes. Plus I'm still a violinist at heart. I like performing. And lecturing is a bit like performing."

Suckling could have made his career as a violinist, too. He spent his adolescence playing in ceilidh bands and the National Youth Orchestra of Great Britain, and since starting the job at York has found himself picking up his fiddle once again. "I gave a little recital in the spring – Bach's Chaconne, Berio's Sequenza VIII, George Benjamin Miniatures, a Biber Passacaglia -" Not exactly a programme that could be trotted out without practice, then. How does a composer with a hefty teaching schedule, who has just been signed to Faber Music, whose commission list is going through the roof, make time for violin practise as well?

He gets up early, for starters. He's often to be found on the 4.50am train from Manchester to York, off to squeeze in some composition work before lectures. "Composing is about being in the right frame of mind, and making a designated space to be so," he says. "But basically no, I can't do it all. I can just about manage to compose and teach, or to teach and play the violin, or to play the violin and compose."

It's probably handy, then, that one of this year's commissions comes in bite-sized instalments. Over the course of this season Suckling is writing a set of musical postcards for the Scottish Ensemble. The first, called In Memoriam EMS, was premiered last month – a striking and atmospheric miniature that lasted only a couple of minutes but whose impact lingered far longer.

"The idea for the postcards came from a conversation between myself and [the Ensemble's director] Jonathan Morton," says Suckling. "Jonathan was leading the London Sinfonietta when they played my piece Candlebird, and afterwards he asked whether I was interested in writing something for the Ensemble. I definitely was; I'd grown up going to their concerts and their approach to string-playing, all their energy and their vibrancy, was very influential on me as a string player."

The postcard format was partially a practical thing. The Ensemble's 12/13 season was already planned and there was no space to shoehorn in a new long work, while four little works could fit nicely within each of the four concert programmes. But the postcards also play with the convention of a composer-in-residence, as Suckling explains.

"The Ensemble liked the idea of working with me because I'm from Glasgow – except I don't live in Glasgow. So we talked about how people keep in touch when they're not in the same physical space. We talked about postcards and how they might work in music."

The way they work is within certain parameters. First is concision. "It's a great challenge to be brief," says Suckling, "especially because I usually try to pack hundreds of ideas and references and allusions into my pieces." He talks about the function of postcards: how they capture specific places in one image, something he feels "uncomfortable with because I don't like tying my music down to a single pictorial representation. My pieces tend to come from a whole mess of things, some of them visual but some literary or philosophical. Anyway, all music is basically about other music, and each listener hears their own set of references." What we won't be getting, then, is the musical equivalent of a postcard from Loch Lomond.

There's also the question of where the postcards are from, and who they are to. Suckling is writing each ahead of time – in that sense it's a postcard to the concert from wherever he's writing – but each one is in some way connected with the repertoire in the concert's programme, making it a postcard from the concert. "Maybe it's a postcard from one concert to the next," he suggests. "My gran used to collect postcards and pin them on her wall until it looked like a kind of mosaic. I like the idea of these concise entities gathering together to form something bigger." And ultimately his four short pieces will make a set. "Like the mosaic on the wall," he says.

Something that struck me about Suckling's first postcard – and indeed about much of his orchestral writing – was his ability to evoke spaces far bigger than the piece itself. How does he go about achieving that in his scores? "Music can work like a smell," he says. "You get a sudden whiff and it'll prompt a certain feeling or memory. Similar thing in music: if I push the right buttons I can open up all kinds of spaces. In that sense I suppose it is a bit like a postcard. A decent one will set off all kinds of associations using just one image."

What can we expect from postcard number two, then? It slots into the Ensemble's candlelit programme called Variations, which contains two of the greatest instrumental examples thereof: Benjamin Britten's Variations on a Theme of Frank Bridge and Bach's Goldberg Variations (in Sitkovetsky's transcription for strings). The postcard is called Jonathan Morton, his Ground, and picks up the variation theme.

"It's a play on the baroque term ground bass," says Suckling, slipping into lecture voice, "in which a melody develops above a repeating bass line" – think Dido's Lament or Pachelbel's Canon. "If the ground – the repeating pattern – is in the bass line, which it usually is, then the harmony is set and the melody can vary. But I've given the ground to Jonathan at the top of the texture, and that has widened the potential variations that can play out."

If all this risks sounding too academic, I doubt that the music itself will be. Suckling's scores are richly packed and intellectually rigorous, but they communicate directly. "I write music to be played and to be listened to," he says. And on that note he goes back to analysing Schoenberg.

The Scottish Ensemble's Variations programme is at Dundee's Marryat Hall on Monday and tours to Oran Mor, Glasgow, Greyfriars, Edinburgh, St John's, Perth, the Music Hall, Aberdeen and Eden Court, Inverness until Saturday, December 8.