Simcock is no stranger to this festival, or any other: he’s a big name on the music circuit, constantly on tour and an accomplished improviser.

Silence is, as John Cage might have said, more easily imagined than experienced. And silent films, historically, were nothing of the sort: they came with music, improvised live on a keyboard, sometimes by performers of distinction.

In the 1920s Shostakovich played piano for the movies in St Petersburg. Next week in Hampstead the contemporary jazz star Gwilym Simcock will be doing much the same, accompanying a screening of the celebrated Hitchcock film “The Lodger” as part of Hampstead Arts Festival.

Simcock is no stranger to this festival, or any other: he’s a big name on the music circuit, constantly on tour and an accomplished improviser.

But this is his first time playing for a film. And he calls the project “a voyage of discovery”, anticipating music that won’t, he says, be “jazzy jazz” - this is, after all, a film that features Ivor Novello in one of the lead roles - but will aim to “pick up on the mood of what’s going on”.

On more familiar ground, Simcock makes another appearance at the festival with “Birdsong” : a song-cycle he’s created with lyricist/singer Kizzy Crawford to texts about the natural environment of a Welsh rainforest (apparently there ARE such things) called Carngaffallt.

An example of folk-jazz fusion that, he says, “follows the cycle of the seasons, dawn to dusk” , it involves a small orchestra of classical instrumentalists well as “multi-media elements”. Any resemblance to the deep-relaxing nature sounds you used to get in British Airways long-haul lounges will no doubt be accidental.

Gwilym Simcock at Hampstead Arts Festival 14 Nov (Birdsong) and 17 Nov (The Lodger), both 7.30pm, St John’s Downshire Hill NW3. Details: HampsteadArtsFestival.com