With Brokeback Mountain dominating the recent Academy Awards, 2006 is shaping up to be a vintage year for camp cowboys.

There were certainly dozens of glittery ten-gallon hats evident at the opening night of Erasure’s first “unplugged” tour in Edinburgh, but none on stage. For perhaps the first time in two decades of outlandish theatrical excess, the veteran electro-pop duo were dressed far more sensibly than their fans.

Having sold about 15 million albums over 21 years together, Vince Clarke and Andy Bell are one of British pop’s great low-key success stories. But in recent years they have struggled to compete in an increasingly youth-dominated pop market. Meanwhile, Clarke married and relocated to America, while Bell endured twin hip replacement operations and publicly revealed his HIVpositive status. A more sombre, grown-up Erasure seemed almost inevitable with encroaching middle age.

The duo have certainly reinvented their back catalogue in more adult-friendly form on Union Street, their latest album. Out go throbbing synthesizers and drum machines; in come twanging steel guitars and banjos. Shiny disco-pop is reborn as country rock. You have to admire their nerve, at least. The Edinburgh show faithfully reflected this shift, with a full band joining Clarke and Bell on an assortment of acoustic guitars, jazzy percussion and backing vocals.

Crucial to the operation was Steve Walsh, the arranger and guitarist, and the co-producer of Union Street, who delivered a pleasing patchwork of textures and tempi throughout the set. Presentation was emphatically low-key, a decisive break from the overblown, Broadway-style productions of previous tours.

At times the wilfully synthetic brashness of “old” Erasure sat a little awkwardly alongside the grainy, crafted understatement of “new” Erasure. But Bell’s powerful voice provided the emotional bridge, switching fairly smoothly between soulful falsetto and rich baritone. Although melodrama is the singer’s default mode, he sounded impressively restrained on sparse torch songs such as Love Affair and How Many Times.

Fortunately, Erasure have not become so grown-up that they have forgotten how to entertain a large crowd.

For the grand finale in Edinburgh, they departed from the Union Street tracks with a barrage of bouncy hits, all rearranged in the new acoustic mode.

Singalong hen-party classics including Oh L’Amour, Sometimes, Love to Hate You, Stop! and a belting encore of A Little Respect, all merged into one long, thigh-slapping, boot-stomping, hog-wrestling hoedown. Yee haw.

Tour details: London, Shepherds Bush Empire, April 19; Gateshead, Sage, April 21.

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