When Cadillac Sky’s album Blind Man Walking appeared early last year, bluegrass fans didn’t know quite what to make of it. These musicians from Fort Worth, Texas, took the generally conservative sound of bluegrass and set it on its head with all-original songs that were, in a word, extreme. They were fast, they were loud, they quoted Marcel Proust on their CD insert (“The real voyage of discovery consists not in seeking new landscapes but in having new eyes”), they broke into a full-fledged black gospel style in one number, they sang lines like “I’m at the mercy of my DNA,” they wrote about stress and insomnia (“poured a bottle of Nyquil in my veins”). Blogs buzzed with news of conflict between the band and bluegrass festival promoters unused to the dynamic range and occasional electronic effects, and indeed the booklet for Blind Man Walking truculently offers “No thanks to the small-minded, high gas prices, and all apathetic soundmen past and future.”

But here’s the thing about Cadillac Sky: they don’t play “progressive bluegrass” or “newgrass” as those terms are usually understood. On one hand, they stick closer to the roots, and on the other they avoid the laid-back jazz and alternative-rock influences that have defined progressive bluegrass from New Grass Revival (who certainly influenced Cadillac Sky) to Nickel Creek. The theme of “Born Lonesome” is as traditional as could be desired, but it’s delivered in extraordinarily broad gestures–“I came out cryin’, wailin’ like an old freight train./Nurse tried to hold me, but I just pushed her away”–delivered in a full-throated vocal and a spacious sound that could just as easily be filled out by rock instruments as by bluegrass ones. The major outside influence on Cadillac Sky’s music is not jazz but southern rock, and they have a knack for making purely acoustic instruments (a didgeridoo in one case) sound as if they’re playing electric guitar power chords. The big sound is balanced in turn by a Manichaean southern Protestantism in which God and Satan contend on the ground of everyday lives.

The only bluegrass band around today that’s remotely comparable to Cadillac Sky is the six-man Mountain Heart, whose high-powered music has been built by the Ark into a local favorite among bluegrass audiences. Cadillac Sky pulls the music even further in a modern, youthful direction, and even if these musicians are caught up right now in trying to outdo a really striking first effort–their recent sophomore CD Gravity’s Our Enemy is as original as their debut but less focused–their efforts bode well for the future of a genre that was almost written off for dead a decade ago.

Cadillac Sky makes its local debut at the Ark on Wednesday, November 19.