Alison Krauss and Union Station at Ravinia

By Mark Guarino

Bluegrass, that ancient, uniquely American music that rises and falls in popularity while always remaining in the undercurrent, meets its past and its future in one of its most popular practitioners: Alison Krauss. At Ravinia Wednesday, Krauss and Union Station, her long-time band of impeccable professionals, performed over two hours of bluegrass in a sold-out show that modernized the music just enough so newcomers can settle in comfortably while remaining true to the delicate harmonies and haunting themes of the music’s roots.

Krauss, a Champaign native, was a child prodigy as a young fiddle player, winning accolades on the festival circuit before becoming a shining new face on what was then considered a dying folk genre. Today, at 34, she is a genuine pop star, sharing the stage with Bono and Slash at this year’s Grammys and beguiling TV screens in videos, two facets of modern marketing that hardly existed in the world of Earl Scruggs or the Stanley Brothers.

Her ace in the hole is Union Station, the band she joined at age 14 to end up becoming its focal point. Wednesday’s show was mapped out more like a revue, assigning equal time to all of the players onstage. Vocals were shared with guitarist-songwriter Ron Block and also guitarist Dan Tyminski, who, it was noted, was George Clooney’s singing double in “O Brother, Where Art Thou?” The show’s middle portion was solely the propriety of dobro player Jerry Douglas. Every time Krauss handed off duties, the show shifted, from melancholy ballads to hardcore, quick-picking jams.

If that wasn’t enough bulk, Krauss dialed her folksy charms into the red. She made a point of delivering a bio of each bandmember throughout the night, laboriously detailing little known facts about each, from the name of the hair products they prefer to the exact name of the species bassist Barry Bales like to shoot on his farm in Tennessee, but the type of animals he’d like to hunt — if he ever has the chance, mind you — in Illinois. Her deadpanned delivery was funny at first, but as the minutes clocked by, it was as if the entire crowd was forced to witness a sleep-deprived woman ramble.

Luckily, music was played too. The core of Krauss’ most recent work are pop-minded ballads, delicate , that also happen to blush with some prime fretwork on all sides.