Arguably the world’s most celebrated trumpeter is not to be missed at the Proms this weekend, says Michael White.

Not much in life comes free (if it’s of any value) but one thing that does is next Sunday’s Prom – for which you have to have a pre-booked ticket but the ticket comes at no cost, courtesy of the BBC. And what you get for your zero payment includes the premiere of a new trumpet concerto given by perhaps the world’s most celebrated, certainly most glamorous trumpeter Alison Balsom.

It’s a grand piece, virtuosic, written specially for her by the jazz/big-band composer Guy Barker. But as she explained the other day when we talked it through, “the score isn’t particularly jazzy. There are jazz elements, but other kinds of music too: it’s a real concerto. And above all, there’s a narrative.

“Guy is a composer who likes to write illustratively, with a storyline. So when the BBC first commissioned this piece, he and I sat down and discussed what it could be about. I mentioned Paradise Lost, which is a book I’ve always loved. And we came up something based on the Fall of Mankind and Seven Deadly Sins – which allows the possibility of very diverse writing and darker colours than you’d hear if I was playing a baroque concerto”.

The fact that it’s a free concert will probably guarantee a pretty diverse audience as well, many of them coming to a classical event for the first time - although Balsom says that audiences for trumpet concerts “are in any case quite broad because of the cross-appeal of the instrument. People who like jazz and big-band are prepared to come and give it a go. And they’re often younger”.

But Balsom is so high-profile these days that her name alone pulls people in. And she’s known not only for conventional concerts but for hybrid entertainments like the play-with-music, “Gabriel” that she co-devised for Shakespeare’s Globe two years ago.

Based on life in London at the time of Purcell, it starred Balsom herself playing a valveless period trumpet alongside the English Concert and a cast of actors. But with forty people onstage, it was an expensive enterprise that she’s been trying to pare down so the show can tour.

Meanwhile there’s a second play-with-music project that she’s working on. She won’t say what it is – “I’m sworn to secrecy” is all you’ll get from her just now – but keep a lookout.

Alison Balsom plays Guy Barker’s new concerto “Lanterne of Light” this Sunday, 7.30pm. Albert Hall. Tickets may be gone by now (booking:bbc.co.uk/proms) but you can also hear it live on BBCRadio 3.