If this is indeed McLaughlin’s final album, as some recent interviews have intimated, it’s a pretty remarkable one to go out on.

There are various reasons for this; it’s the first bona fide full-scale return to Mahavishnu Orchestra material since the final incarnation of that band waved goodbye in 1975; it was recorded live on 8th December 2017 at the Warfield Theatre in San Francisco, witness to the legendary Friday Night At San Francisco session in 1980; and the album was mixed at London’s Eastcote Studios, one of the city’s last great recording studios, deep in one-time hippie enclave Notting Hill.

McLaughlin’s usual 4th Dimension band (Gary Husband on keys, Ranjit Barot on drums, Etienne M’Bappe on bass) is joined here by fellow guitar hero Jimmy Herring and band (too numerous to mention). The result is pretty wild; if anyone expected John to go out quietly, they were sadly and delightfully mistaken.

It’s also no accident that Herring is best known for playing with a Grateful Dead tribute band (Jazz Is Dead) – the collision of styles and instruments here may bring to mind that countercultural supergroup, emphasised by Marq Spusta’s sumptuous psychedelic cover art.

But of course it’s McLaughlin who regularly catches the ear here, laying down inspired, manic solos with an angry fuzztone, foregrounding brave, unpredictable melodic intervals and highly intricate rhythmic subdivisions. Herring is a nice foil though, his sprightly tone and logical, sometimes lyrical solos occasionally reminiscent of Eric Johnson.

Pleasingly, there’s a lot of emphasis on Mahavishnu Mark 2, with sundry material from 1975’s Visions Of The Emerald Beyond; ‘Earth Ship’, ‘Eternity’s Breath’ and ‘Be Happy’ are particular highlights. But when ‘The Dance Of Maya”s opening riff snakes into action, it’s impossible to resist a chill running up the spine. That churning groove is milked for all it’s worth, at a slightly slower tempo than on the original.

The only minor gripe is with the drum department. Barot and Jeff Sipe’s kits and playing styles are similar, and both players sometimes lack the R’n’B-flavoured groove instincts that Mahavishnu masters (Billy Cobham, Narada Michael Walden) had in spades.

And, in terms of instrumental momentum, if no one else quite comes up to McLaughlin’s level here, that’s no disgrace. Who really has throughout his career, with the obvious exceptions of Miles, Keith Jarrett, Herbie Hancock, Wayne Shorter, Michael Brecker and Jan Hammer?

McLaughlin’s message is still that an open mind and peaceful heart are the keys to both musical and human progression – that hasn’t changed much over the years. And also that good music needs an element of madness. Anyone who has found solace and inspiration in his work over the years, as your correspondent has, will find this a moving and important album.