Once the O Brother, Where Art Thou? soundtrack hit big on the charts, was there any doubt an O Sister would follow?
There is nothing record execs like better than sequels, so you figured rival labels would begin planning an O Cousin or O Granddaddy sound-alike as soon as the Mercury Records soundtrack to the Coen Brothers' film arrived last December.
O Brother, which features classy interpretations of country, blues, gospel and other Depression-era sounds, has sold more than 2.7 million copies, making it one of the year's top dozen sellers.
The good news about Rounder Records' new O Sister! The Women's Bluegrass Collection is that it is not a cheap exploitation package. The 19-track CD is a wonderfully appealing companion piece to O Brother, reflecting much of the latter's warmth and spirit without trying in any way to duplicate its musical styles.
Where O Brother producer T Bone Burnett took various country, bluegrass and gospel artists, from Emmylou Harris to Ralph Stanley, into the studio to record vintage tunes, Rounder co-owner Ken Irwin simply turned to the folk and roots-music label's vaults for recordings that fit the new album's bluegrass theme.
One reason O Sister! asserts an independence is that the collection was in the planning stages long before O Brother hit the stores. Irwin said this week that the album was one of several concept collections designed to celebrate the label's 30th anniversary last year.
In fact, the reason there is no mention of the O Brother album in the liner notes is that they were completed before someone came up with the idea for the O Sister! title during a marketing meeting a few months ago.
The tie-in is natural because some artists on O Brother, including Alison Krauss and the Cox Family, have recorded for Rounder, which has been a major force in keeping alive some of America's musical traditions. A four-disc retrospective, Roots Music: An American Journey, has just been released.
Bluegrass is just one of several components to O Brother, but it is the sole focus in the new Rounder album - though the tracks offer a range of contemporary country and gospel touches. The liberating element is that the vocals are all by women.
Ever since Bill Monroe pioneered the lively bluegrass style in the 1940s, the sound has been characterized by bright instrumentation (heavy on banjo, fiddles and dobro) and high-pitched male vocals.
Given the pop-minded direction of country music in recent years, it was little short of revolutionary when O Brother was named album of the year, and its key track, the Soggy Mountain Boys' "I Am a Man of Constant Sorrow," was named single of the year recently by the Country Music Association.
Its commercial momentum is likely to make O Sister! a bonanza by bluegrass sales standards. Krauss' 1995 album, Now That I've Found You: A Collection, sold more than 2.5 million copies, but that's because some tracks were contemporary enough to gain considerable country radio exposure.
Generally, however, bluegrass artists are considered successful if they sell 20,000 albums. Before O Brother, the outlook for O Sister! might have been around 10,000 to 15,000, Paul Foley, Rounder's general manager, estimated. Thanks to O Brother's coattails, the label now believes 50,000 is a conservative projection.
But you don't have to be an O Brother fan to enjoy O Sister! For anyone who has been entranced by the purity and character of the singing of Emmylou Harris, Krauss and Dolly Parton (in her traditional style), O Sister! should be a treat.
Robert Hilburn is a reporter for the Los Angeles Times, a Tribune Publishing newspaper