Let's just say it: the Steeldrivers are to bluegrass what Charlie Parker is to jazz, what Ezra Pound is to modern poetry. Parker, a master of traditional jazz forms, extended them, adding a fresh batch of new to the mix and transformed his field into something fresh and current. Pound looked at the poetry of his day and formed his famous maxim, make it new, and proceeded to do so.

This is what the Steeldrivers have done to bluegrass.

It isn't as though they've rejected the traditions of the music. No, they are masters of their field and have all of the standard bluegrass runs and patterns down pat, but they also realize that the music doesn't need to end there. They bring rock, honky-tonk, folk, r&b and a touch of classical music to the mix so that what results is as far beyond standard bluegrass as an ocean is beyond a glass of water. All told, Hammer Down is a brilliant album.

The first four songs tell us where this album is headed. It opens with "Shallow Grave," a contemporary take on the traditional Appalachian murder ballad written by new lead singer Gary Nichols, but then it segues to an upbeat folky tune called, "How Long Have I Been Your Fool." This song leads to a rocking cheating song written by Nichols and fiddler Tammy Rogers. By the time we get to a classical-based ballad, "I'll Be There," it's evident that we are in the hands of master musicians determined to take on a musical tour of their minds and emotions. It's a trip worth taking.

Rogers, who plays fiddle, viola and cello as well as contributing harmony vocals and co-writing three songs on the album, is the soul of the Steeldrivers. Her sound is all over the album, offering a fiddle response to the lines of Nichols' lead vocals, playing melodic intervals to the banjo's lines and singing. Remove her from the mix and you've got a very different album.

Nichols, the band's third lead singer in as many albums, had big shoes to fill and he does it admirably, sounding as though he's been one of the band from the beginning. With his Muscles Shoals background, he brings a soulful quality to the vocals that helps move the Steeldrivers in the new direction they are taking.

If you want to hear a first-rate bluegrass band delivering fine music in the tradition while at the same time making it new by moving that tradition into the future, the Steeldrivers are for you.