"To see Paul McCartney dancing with our dancers, I couldn't believe it!" Moloney says. "And he's really good, too."

The Chieftains have lent a shamrock flavor to records by artists from Sting to the Stones to Willie Nelson to Ziggy Marley. But their own path is a study in the persistence of simplicity. When Moloney formed the group in 1962, Irish music was seen primarily as boisterous pub sing-alongs or tragic sentimental tunes. Instead, the Chieftains opted for old-time jigs, reels and polkas.

Of late, Moloney has explored what he calls bluegrass-greengrass music, connecting the O Brother phenomenon with its ancestral roots. The Chieftains have collaborated with A-list Americana artists on two records, Down the Old Plank Road and Further Down the Old Plank Road.

"Much of the music is the same, only with different lyrics," he offers. "Joe Ely does 'I'm a Moonshiner' from the Irish 'I'm a Rambler.' And the Irish melody 'Shady Grove' is what you know as 'The Cotton-Eyed Joe.' There's a huge connection."

The first record included a collaboration with Lyle Lovett, who was recuperating at the time from that nasty encounter with a bull. "I told him that he wasn't getting out of it, even if I had to bring [a recorder] to the hospital," Moloney says with a laugh.

The Chieftains previously collaborated with Houston Ballet, and Moloney's son is a space engineer with NASA, which brings the musician to the area frequently. "They sent one of my tin whistles up in space and presented it to me in a glass case on stage in Houston," Moloney remembers. "Talk about an honor."