By Mandi Bierly
Updated March 19, 2007 at 12:00 PM EDT

Nickel Creek mandolinist Chris Thile (pictured) officially christened his new band the Tensions Mountain Boys Saturday night with a gig at New York’s Carnegie Hall. Actually, the bluegrass quintet played Carnegie’s 599-seat Zankel Hall, which ever-clever Thile noted before announcing that while they were not nervous, they were slightly surprised to see the audience sitting there in their underwear. (Especially when the Boys had made a point to wear suits for the occasion.)

Presumably, Thile’s main source of stress was the world premiere of his 40-minute suite “The Blind Leaving the Blind,” which he penned for himself (mandolin/lead vocals), Chris Eldridge (guitar), Greg Garrison (bass), Noam Pikelny (banjo), and Gabe Witcher (fiddle) — the equally-talented musicians behind Thile’s acclaimed 2006 solo album, How to Grow a Woman from the Ground. (If you haven’t checked it out, you should: He covers the White Stripes’ “Dead Leaves and the Dirty Ground,” the Strokes’ “Heart in a Cage,” and Gillian Welch’s “Wayside [Back in Time],” while also offering speed-picking and heart-breaking originals like “The Beekeeper” and “You’re an Angel, and I’m Gonna Cry.”)

But back to “The Blind Leaving the Blind.” Thile needn’t haveworried. The piece — four movements of mingling vocals andinstrumentals weaving a tale of innocence lost — received a standingovation. I wish I could describe it to you in depth, but the fact is, Ididn’t want to take notes. I just wanted to listen. (Which is acompliment to the band — and a reminder to myself that I should stickto reviewing TV and DVD, which I can rewind).

Following the warm reception, Thile said he needed a minute for hisaccelerated heart rate to drop, so Pikelny stepped to the mike and toldthe story of the first time the band played the suite’s particularlychallenging fourth movement on stage a year-and-a-half ago. They toldeach other it wouldn’t matter if you screwed up; if you couldn’trecover and continue playing, all you had to was say, “What!“When Thile insisted they recreate that original attempt, Eldridgequickly shouted it in his best Dave-Chappelle-as-Lil-Jon voice.

It wasat that moment that I found a new respect for bluegrass, whichadmittedly, my knowledge of until recently consisted of Nickel Creek’slive cover of Britney Spears’ “Toxic” (which should resurface, BTW, during their Farewell (For Now) tour, which kicks off next month). It’s not just because its younger generation watches Comedy Central — 26-year-old Thile is also a big South Parkfan, incidentally. It’s because I realized these musicians can neverphone in a performance. “The Blind Leaving the Blind,” with its manystops, starts, and mood changes, won’t allow it.

As the Tensions Mountain Boys continued the concert with songs from How to Grow a Woman from the Ground,I had two other revelations: People will yell “Whoo!” in the middle of asong at Carnegie Hall (or okay, Carnegie’s Zankel Hall), if the fingersare a-flyin’. And after two encores, you can spot two men seated in rowF actually high-fiving.