There are not enough superlatives in the English language to describe how good Alison Krauss & Union Station are at performing bluegrass. Krauss is simply the most gifted vocalist—of any genre—in the world, and she’s long surrounded herself with the finest collection of pickers money can buy (even before she had the money to buy them). While Union Station could presumably be susceptible to cries of “too polished!” from those who like their bluegrass dipped in moonshine and molasses, the only way to beat them in a bluegrass competition would be to create the bluegrass equivalent of IBM’s Deep Blue, the chess computer which famously defeated the Russian genius Garry Kasparov in 1997. Only in the bluegrass computer’s case, it would be called Deep Bluegrass, and Krauss and Union Station would prevail. With Jerry Douglas. MIKE SEELY

Fri., July 8, 7 p.m., 2011