You’re already familiar with Dan Tyminski whether you realize it or not.

Currently Alison Krauss and Union Station’s resident guitar and mandolin picker, Tyminski lent his stark bluegrass tenor to the singing voice of George Clooney’s character in the Coen brothers’ 2000 film, O Brother, Where Art Thou?

His performance of “Man of Constant Sorrow” as part of the Soggy Bottom Boys helped the song win a Grammy, and generate enough sales of the soundtrack to go eight-times platinum.

Tyminski’s string and vocal talents have supported Krauss and Union Station for 18 years now, and while they’ve played the globe, won a gamut of awards, and even performed for three consecutive U.S. presidents, a show never passes without taking a little bit of a toll.

“No matter where I play or who I play for: I have butterflies for the first few minutes of every show I do,” he said. “It’s not crippling, but those couple little butterflies always float around before I settle into my comfort zone.”

Tyminski confirmed that same level of nervousness when playing for Presidents Clinton, Bush, and Obama, but for reasons one wouldn’t expect.

“It’s more difficult to play the real small audiences than the large ones, and those East Room shows [in the White House] always had smaller ones,” he said. “You tend not to feel the worry when you’re playing for more people.”

Currently riding another massive wave of success from last year’s Grammy-winning Paper Airplane, little has changed Krauss and Union Station’s approach to the recording studio, although they’re now spanning their fourth decade of activity.

They still meet to discuss which tunes to record, whether original numbers penned for the band by industry veterans like Elvis Costello and Jackson Browne, bright up-and-comers like Aoife O’Donovan or old-timey folk-standard writers like Tim O’Brien.

Tyminski sings the latter’s uptempo bluegrass number “On the Outside Looking In” on Paper Airplane, and said that it was as simple a choice as any they’ve made in all their time as a group.

“That was one of those that was easy,” he said. “We all raised our hand — there was a five-way tie for ‘Yes, let’s do it.’”