I'm thrilled that next Friday in Glasgow's City Hall, the SCO and the Swiss Piano Trio will give the first performance of Lyell Cresswell's new Triple Concerto, to be repeated the following night at the Queen's Hall in Edinburgh.

There are reasons both personal and professional for my delight.

New Zealander Cresswell and I have known each other for a long time. We were contemporaries in Aberdeen – he was a post-grad composer, I was an undergraduate. One thing always intrigued me: Cresswell would let me see the scores of his music, but I never got to hear a single note. Things might have been happening slowly for him in his home country, but nothing happened here. None of his music was played at university, except perhaps the occasional small piece or arrangement in the context of a chamber music society concert.

It struck me as odd, as I felt instinctively that Cresswell was the real McCoy: a highly individual McCoy, for sure, but the McCoy none the less. Things seemed to be looking up when, in the late 1970s, he won an award – the Ian Whyte Award – that led to the SNO playing his orchestral piece Salm, which received a few performances before apparently going back onto the shelf.

Nowadays Cresswell's music is performed and recorded internationally, and I've watched it develop and grow – and speed up. He used to write music that was slab-like and massive: it tended to move slowly, or that was my perception. Dramatically, years ago, his music began to move more quickly, as he confirmed in a formal interview.

But most striking of all is the change in Scotland's musical landscape in our time. Today's young composers can write their music in institutions such as the Royal Conservatoire of Scotland and there is the potential for their compositions to be played, as that institution demonstrates 30 to 40 times a year during its new music festival, Plug, and elsewhere. Four decades ago, as Cresswell could confirm, this was totally unthinkable. Changed days.