Irony abounds in the title of Girls in Peacetime Want to Dance, the ninth album by the Scottish collective Belle & Sebastian. It goes unstated that the record was released in an atmosphere not quite synonymous with peace, but the group unquestionably want to dance, spending nearly half of this lengthy record grooving to a neo-disco beat. To approximate the pulse of a mirror ball, Belle & Sebastian hired Ben H Allen, a producer best known for his work with the modern psychedelic troupes Animal Collective and Washed Out, a decided shift away from the exquisitely sculpted miniatures that populated B&S' two records with Tony Hoffer, particularly Write About Love. If that 2010 album found the band embracing their eccentricities and taking the time to whittle their quirks down to their basic elements, Girls in Peacetime Want to Dance finds the group stretching way out, twice taking as long as seven minutes to complete a cut and only once flirting with the three-minute mark. Surely, the grandest formal experiments are the longest tracks -- "Enter Sylvia Path" plays like a slyly decadent 12" mix and "Play for Today," featuring Dee Dee Penny of the Dum Dum Girls, is a duet with de facto leader Stuart Murdoch -- but even the relatively concise "The Party Line" bears a heavy four-four thump, and "Perfect Couples" percolates with polyrhythms previously unheard on Belle & Sebastian's records. Next to these brazen departures lie a few songs where flashy production tricks are grafted upon pleasingly familiar B&S forms (the hard swing and fuzz of "Allie," the analog whine on "The Power of Three," the Motown bounce of "The Book of You'), along with reassuringly meditative ballads and the remarkable "The Everlasting Muse," which takes a sharp left turn from jazz to woozy folk. This is the sound of a band that's growing fearless in middle age, and while the record occasionally does drag -- all those long songs push it over an hour, but the sequencing makes it feel even longer -- there's also a thrill hearing a band unafraid to stumble.