SOMEWHERE amidst the frequently unintelligible Bard-speak of Baz Luhrmann's stylised 1996 film, Romeo + Juliet, there's a lovely, quiet moment when Romeo (Leonardo DiCaprio) encounters Juliet (Claire Danes) at the "old accustomed feast" at Capulet's house.

Shortly afterwards we see the couple again, at Juliet’s balcony. What both scenes have in common is a stirring piece of music written for piano and strings by Glasgow-born composer Craig Armstrong, OBE. It taps into the astonished emotions of Juliet and Romeo as they realise the feelings they have for each other.

Armstrong won Bafta and Ivor Novello awards for his score, and the balcony theme is still one of my favourite pieces of music.

“Of course, there are scenes where you have to write specifically dramatically but when you don’t, you try and write the most beautiful piece of music you can,” he said a few years ago. “The real trick is to make music and film work together. When it all actually comes together as it should, it becomes bigger than the constituent parts; you’re creating an artform that isn’t film and isn’t music. It’s a synergy of both. If that happens, you’re having a good night.”

With all his melodic strengths, he has had innumerable good nights since Romeo + Juliet, on films as disparate as Orphans, The Bone Collector, Moulin Rouge!, The Quiet American, Love Actually, World Trade Center, Ray and Wall Street: Money Never Sleeps.

But he is nothing if not prolific, to the extent that there have been solo albums, orchestral works, theatre commissions and more. He has worked with everyone from the Pet Shop Boys to Mogwai.

His latest collaboration comes on Friday at the Labyrinth of Light art installation/concert at the Old Fruitmarket, Glasgow, alongside artist Jim Buchanan and others. If you haven’t discovered Armstrong’s emotionally charged music yet, this is as good a place to start as any.