Violin, trumpet, piano, saxophone and speaker/singer…it’s a curious (OK, perverse, impracticable) combination for a chamber-music group, and one that you’re unlikely to find anywhere but Counterpoise: the odd ensemble set up seven years ago by music critic Barry Millington and trumpet-player Deborah Calland which has proved a hit with audiences for the very reason that it’s odd.

Able to do things that a more conventional ensemble can’t.

As Millington and Calland are both resident in Hampstead Garden Suburb, it’s surprising that their strange invention hasn’t, until now, played the St Jude’s Proms.

But the time has come.

And on the 30th it offers “An American Dream”: a programme of music and words that takes inspiration from a prose-poem by Walt Whitman that celebrates the idea of America as a home for the homeless.

“Immigrants arriving, fifteen or twenty thousand in a week/The carts hauling goods, the manly race of drivers of horses, the brown-faced sailors…a million people, manners free and superb” – so it runs on, getting ever more excited and ever more in conflict with the spirit of closed borders and Trumped-up walls that governs much of the world right now.

“As programmes go, it’s topical”, says Calland.

“And although it’s principally about the Dream, we also look at those who haven’t done so well from it”.

With poems by the pioneering black writer Langston Hughes, songs by Gershwin, Copland and Britten, jazz numbers by Dizzy Gillespie, and tangos from south of the border by Piazolla (who certainly wouldn’t get through Donald Trump’s defences if they ever happened), it’s a sweeping range of repertoire. And fronting all the speech and singing is the young, Jamaican-born bass Robert Winslade: a performer who made instant impact in the BBC Proms last year.

“He was singing Bernstein, unaccompanied”, says Millington, “and it was stunning. So I booked him. It seemed like a good idea until it turned out that his wife was pregnant and the baby due around St Jude’s time.

“Hopefully it won’t all happen on the day we do the show”.

Counterpoise present An American Dream, Thurs 30, 7.45pm, St Jude’s Church, as part of Proms at St Jude’s.