Post Electric Blues may go down in the books as Idlewild’s own In Rainbows -- that is, the album that’s best remembered for its free-of-charge release, regardless of the music’s merit -- but it’s also a strong, polished rock record. There have been many different incarnations of Idlewind over the years; the guys seem to change directions as many times as they change their membership, and the sound gets revised with each switcheroo. On Post Electric Blues, they’re a worldly pop/rock band, showing off their Scottish roots on the Celtic numbers and channeling the American heartland with songs like “Younger Than America.” Much of the material sounds indebted to Roddy Woomble’s solo career, which launched in 2006 and spun off two intimate, acoustic folk albums. The folk melodies are still present on these 11 tracks, but they’ve been blown up to epic rock & roll proportions courtesy of Woomble’s bandmates, who tone down the punky messiness of their early material and focus on clean contributions, bright colors, and tidy hooks. Semi-anthems like “City Hall” and “Readers & Writers” are strong enough to attract those fans who still pine for the band’s punky period, while the quieter numbers -- “(The Night Will) Bring You Back to Life,” “Take Me Back to the Islands” -- are aimed at those who prefer their Idlewind songs to swoon instead of sweat.