Carlos Guitarlos, Borderline, London

It's an edifying coincidence that Carlos "Guitarlos" Ayala should play his first gig in the UK in the same week that heavy-metallers-in-meltdown rockumentary Metallica: Some Kind of Monster was released.

It's an edifying coincidence that Carlos "Guitarlos" Ayala should play his first gig in the UK in the same week that heavy-metallers-in-meltdown rockumentary Metallica: Some Kind of Monster was released. Ayala could have used a $40,000-a-month "therapist/performace-enhancement coach" when his life fell into an abyss of alcoholism, divorce, drugs, homelessness and near-death in the 1990s.

Before this personal apocalypse, Ayala was a key figure in LA's 1980s blues-punk underground, which included acts such as Los Lobos, The Blasters, Fear, X and his own band, the notoriously hard-living Top Jimmy and the Rhythm Pigs. After the Rhythm Pigs imploded in 1987, Ayala became a busker on the pavements of San Francisco, strumming for commuters' change on the transit plaza in the city's sleazy Mission district.

Tonight, Ayala confesses that the moving title track of his latest album, Straight from the Heart - one of the most acclaimed US blues releases of recent years - was written "on his deathbed", as he recovered from near-fatal congestive heart failure brought on by cocaine, booze, diabetes and a punishing life in the gutter. The 54-year-old is a beefier on-stage presence than you'd expect from his wraith-like album-cover photo, but the Shaolin-master grey beard, lack of teeth and deep facial fissures are testaments to a life that would have made a member of Metallica squeal like a disconsolate piglet.

Playing beauty to his beast is Marcy Levy (Marcella Detroit of Shakespears Sister in a former incarnation, as well as a backing singer for the likes of Aretha Franklin), who performs a beautiful acoustic version of her biggest hit, "Stay". Her soaring soul voice forms a workable counterpoint to Ayala's, which in its scraped-out throatiness is reminiscent of Eddie Hinton, Muscle Shoals' white-soul wunderkind, whose self-cauterising lifestyle and early death Ayala has almost imitated.

The Muscle Shoals comparisons do not end there. The best track on Straight from the Heart, and the second song Ayala plays tonight after the bumptious bajou-beat of "Damn Atchafalaya", is "The Love I Want", as good a country-soul ballad as you will hear this side of anything Dan Penn and Spooner Oldham wrote for the likes of Percy Sledge or James Carr. Similarly, "Ain't That Lovin' You" - described by Ayala as "heavy Motown" - is a sexy, robust slab of roadhouse funk, powered by the kind of chugging chords that bassist James Jamerson - the most gifted of the Funk Brothers, the Motown backing band - excelled in.

After the heartfelt sentiments of "Straight from the Heart","Women and Whiskey" indulges a little too much in lachrymose blues clichés, but the barrelhouse boogie of "Dance with Your Baby" makes up for it - as do honky-tonk covers of Robert Johnson's "When You Got a Good Friend" and "Ramblin' on My Mind". Ayala's way with a Fender Stratocaster is exemplary - you'd expect nothing less from a man whose guitar-playing has graced the likes of Tom Waits' classic swordfishtrombones.

The only real disappointment is that Ayala decides against playing more tracks from Straight from the Heart, which has some great songs, ranging from Terry Callier-style jazz-folk to jumping blues and rockabilly. But at least he's alive.