Ahead of a special fundraising show at Lauderdale House, the musician talks to Alex Bellotti.

When John Etheridge last appeared in this paper’s pages in February 2014, he was threatening to chain himself to one of three copper beech trees due to be cut down at Kenwood House.

Having succeeded in saving them, and ever the local activist, the South End Green musician is now turning his attention to the fate of Lauderdale House, which he will play on July 9 to help raise money for its £2.1m redevelopment plan.

The Highgate institution holds a special connection with the acclaimed jazz guitarist; when it launched its biannual ‘Jazz in the House’ season 15 years ago, he was one of the first acts to perform there, appearing with his band, Sweet Chorus, who will also return next week at the ‘Picnic Jazz’ event.

“Lauderdale is a very worthwhile… actually that’s a horrible word – it’s a lovely house, but it’s in desperate need of refurbishment,” Etheridge says when we meet at a Hampstead Heath cafe.

His first Lauderdale appearance came shortly after the formation of Sweet Chorus, which he notes started as a tribute to his departed friend Stéphane Grappelli. The iconic French jazz violinist, who died in 1997, was famously also a huge influence on another Hampstead musician, Nigel Kennedy.

“I’ve worked with Nigel for years, he’s always treated me reasonably with respect which is quite rare,” laughs Etheridge. “I was playing with him last year in fact because of the Grappelli connection; we met when he must have been about 18 and he used to come along and play with us.”

A teacher as well as a musician, the 67-year-old is keenly aware of how the art of guitar playing has developed over the years.

He puts his own distinct style – and indeed the various styles of his contemporaries – down to the fact that any attempt to imitate another musician was too difficult in the days before you could learn a “tricky lick”, for example, by using an app to slow down a song.

“I’m inspired by millions of people and I used to sit down and try to work out people’s stuff; it’s quite enjoyable but I never got too far into it. If I wanted to, I’d have had to get the needle down, put my thumb on the record, then take the needle off and try to remember it.

“So because of that – and because there were no books about how to hold a pick, what finger to use – so many guitarists of my generation have their own style.

“Albert Lee, Richard Thompson, Jim Mullen, Allan Holdsworth – everyone’s playing in a style that they put together because they didn’t no any better. Nowadays everybody’s technically adept, but has the same technique as everybody else.”

Before Grappelli introduced him to the gypsy-jazz genre ‘Hot Club’ which Sweet Chorus play, Etheridge first rose to prominence as a member of progressive-rock band The Soft Machine.

After the band’s surviving members reformed as Soft Machine Legacy in 2004, the guitarist has noticed a resurgent underground interest in the genre which even has some high-profile backers.

“I went on a progressive rock cruise last year with Soft Machine and there were 3000 people paying $5000 each. Steve Wozniak [Steve Jobs’s successor as Apple’s CEO] was there and he was the epitome of people on that boat – in their 50s, with a beard, and the most intense of fans.

“What I notice about [prog] now is how ambitious it all is; how out of the box it is. Anything is possible and you can try anything out and put it in. Everyone can laugh at the 20 minute rock operas and some facets of it were laughable, but the expansiveness of it meant we could take it anywhere and for a while there were a lot of people coming along with us.”

Like all the great jazz musicians, Etheridge remains a prolific live performer and alongside Sweet Chorus, Soft Machine Legacy and countless other projects, he has also established an ongoing guitar duo with John Williams.

In a sign of the times, he’s noticed how the dawn of YouTube has subtly changed the nature of gig nights, and when he’s not being chained to a tree, he’s not always so appreciative of cameras.

“I saw an absolute classic of a modern gig the other day, where I was asked to sit with a band. There were probably two people in the audience, but they had the video all set up and the whole thing’s appeared on YouTube as if it were some sort of landmark gig, even though there was no one actually there!”

So there’s the deal for his Lauderdale show: if you want to get a photo, you best bring a crowd.

John Etheridge and Sweet Chorus plays Lauderdale House’s Picnic Jazz on July 9. On-the-Door Prices: £15 (£12 Concs); £50 Family Ticket for four; £110 Picnic Table for six. Phone 020 8348 8716 or visit lauderdalehouse.co.uk Etheridge also joins violinist Aaron Weinstein on July 14-18 at The Crazy Coqs at Brasserie Zedel in Sherwood Street, W1 in a tribute to Stephane Grappelli.crazycoqs.com 0207 7344888