Having pottered along for almost 10 years, noticed by few apart from adulatory rock critics, Ohio's Black Keys have finally hit commercial paydirt with the album Brothers, which reached No 3 in the US. Its murky mix of blues and Muscle Shoals funk has filled a White Stripes-shaped void, and if singer-guitarist Dan Auerbach and drummer Patrick Carney don't quite have Jack and Meg's ear for melody, it didn't keep the album from selling 73,000 copies in its first week.
At a sold-out Roundhouse, though, it wasn't the White Stripes that came to mind but Ten Years After and Humble Pie, early-70s British blues-rockers whose mastery of the meandering jam was swept away by punk. Auerbach is of near-virtuoso standard, and spent 10 minutes at a time simply ambling along the fretboard, producing both succinct, killer riffs and prolonged journeys into the blues swamps. He had a Hendrixy way of singing along to his riffs, while Carney's deft use of his drum created a bassline. It wasn't always interesting, but their rock-solid musicianship compelled the mainly middle-aged crowd to nod along with increasing velocity.
The result was a remarkably full-figured sound, which made it easy to forget there were only two people making it. And one of them was only half the man he used to be, so to speak: Auerbach's formerly luxuriant beard has been trimmed down to well-groomed fuzz, rather as the Kings of Leon did when they started selling albums.
Alhough reputed to have once been considerably more extroverted, Auerbach spent the evening in a bubble of concentration, turning Brother's relatively snappy songs into extended flights of fancy. Joined by a bassist and keyboardist halfway through, he and Carney played till both they and the fans were worn out. As they ended, a woman in the balcony, lost in blues-rock rapture, tipped an entire pint of beer over the audience below.
At Hyde Park, London, on Wednesday. Box office: 0844 277 4321. Then touring.