Country music’s surprise success story of 2001 continues to build and expand that success.

The double-platinum-certified soundtrack O Brother, Where Art Thou? became two concerts, a documentary film of one concert and a soundtrack of that film. Next, it’s being planned as a national tour.

Patty Loveless –- who is not on the soundtrack -- is expected to join original O Brother contributors Emmylou Harris, Ralph Stanley, Alison Krauss and Union Stationand Norman Blake on a 20-city U.S. tour next January and February.

A concert by the soundtrack cast at Nashville’s Ryman Auditorium last year was followed by one at Carnegie Hall earlier this year, and plans for a Hollywood Bowl show this year had to be scrapped due to scheduling difficulties. Nashville representatives of several artists from the soundtrack say booking agents are exploring tour possibilities and schedules for a tour to run from Jan. 25 to Feb. 23. No dates or cities are set as of yet.

Drawn from the Coen Brothers’ movie of the same name, O Brother exploded the Nashville shibboleth that bluegrass doesn’t sell. The album -– which also includes blues, gospel and old-time country music -- has dominated the Billboard Top Country Albums chart for much of this year, is No. 1 on that chart and is No. 1 on the Billboard Top Soundtracks chart.

The Ryman Auditorium concert last year was filmed for the current documentary Down From the Mountain. The accompanying soundtrack, Down From the Mountain: Live Concert Performances by the Artists & Musicians of O Brother, Where Art Thou?, entered the Top Country Albums chart dated Aug. 11 at No. 10.

Building on a bluegrass revival, the group Nickel Creek’s debut album has been a Top 20 Billboard album, has charted for 34 weeks and has gotten extensive CMT coverage. Bluegrass AC/DC tribute band Hayseed Dixie’s debut album has been on the Billboard albums chart for 15 weeks. Country veteran Loveless’ recent return to the music of her Kentucky youth with Mountain Soul has drawn glowing reviews. Also represented on the Billboard chart are roots albums by the Del McCoury Band, Krauss and Harris.