Album: Elton John & Leon Russell, Union (Mercury)

Back on the cusp of the 1970s, a young Elton John was making his American debut at Los Angeles' legendary Troubadour club, where he was thrilled to meet his idol Leon Russell, the saturnine pianist then on the verge of establishing his own solo career after a decade as a sought-after session man.

Russell had been a crucial component of Phil Spector's The Wrecking Crew, also playing on records by The Byrds, The Beach Boys, Frank Sinatra, Bob Dylan and Joe Cocker, whose career he revolutionised as musical director of the Mad Dogs & Englishmen tour. Along the way, Russell devised his own style, a blend of gospel and swamp-rock, and developed into a songwriter of note, penning standards such as "Superstar", "Delta Lady" and "A Song For You". Stars like the Stones, Beatles and Clapton queued up to play with him. By contrast, Elton John was just feeling his way into the business, but within a few years would dominate it. But while their mutual admiration society continued throughout the decades, the two piano men didn't collaborate until Elton heard his partner playing a Leon song while on holiday, and was so moved by memories that he burst into tears. A phone call later, and The Union was organised.

And hearing how well they work together, one's only regret is that they didn't do it years ago. The album is easily the best thing either of them has produced for years, full of polished songwriting, rolling rock grooves and effortlessly classy musicianship from all involved. Tracks like Jimmie Rodgers' "Dream" and the pounding pow-wow rocker "Hey Ahab" find Elton returning to Tumbleweed Connection territory, while the lachrymose duet "When Love Is Dying" has the melancholy nobility of a future standard, akin to Bonnie Raitt's "I Can't Make You Love Me". Other highlights include "A Dream Come True", a galloping shuffle which recalls The Band with Levon Helm in the driving seat; the rolling New Orleans swamp-funk of "If It Wasn't For Bad"; and "Monkey Suit", a raunch-rocker in louche Stones style. Best of all, perhaps, is "Gone To Shiloh", a haunting civil war tale that's like an equivalent of "The Night They Drove Old Dixie Down", with Leon and Elton trading verses with Neil Young over slow sea-swell waves of piano: "After all this, if we should prevail, heaven help the South when Sherman comes their way."

A few years ago, Don Was would have been the natural choice as producer, but he's been irrevocably replaced as helmsman of this kind of heritage-rock project by T-Bone Burnett, who produces another sterling result here, demonstrating how intimately he understands what made both these performers so individually successful in the first place, while locating the place where their distinctive voices – Leon's deep drawl and Elton's stentorian croon – can cohabit comfortably.

DOWNLOAD THIS Gone To Shiloh; Hey Ahab; When Love Is Dying; If It Wasn't For Bad; A Dream Come True