August 14th was one of those perfect mellow summer evenings, a great night to lounge on a beach towel at Central Park’s Rumsey Playfield and take in a little music. Even if the band was crap, it would have been a pleasant way to spend a couple hours. I knew nothing of Nickel Creek, except that some bluegrass-musician friends of mine raved about them. Fiona Apple was also on the bill; I’d seen her on TV once or twice, and thought she wasn’t bad. The tickets were cheap, the weather balmy; it seemed worth a shot.

Well, serendipity was on my side, my friends. Nickel Creek turned out to be one of the most dynamic bands I’ve seen in a while – three tremendously talented musicians (four if you count the bassist they’ve added to the line-up) who were just having a whale of a good time on stage. I never knew a fiddle, mandolin, and acoustic guitar could produce such a fat sound, or take bluegrass in so many different directions – indie rock, jazz, jug band, alt balladry. They seemed to be channeling Dan Hicks one minute, Wilco the next, followed by the Grand Ol’ Opry; they even had their Prairie Home Companion moments, loopy stage banter and all.

Bluegrass may be in their blood, but this stuff is a far cry from what I’ve seen Bill Monroe and company play down in Beanblossom, Indiana. They’ve got youth on their side, for one thing (the band’s been playing together since 1989, but they were literally just kids then). Frontman Chris Thile, in his indie black jeans and gelled Jude Law hair, can play that mandolin like a demon possessed, but he can also sing like Ben Gibbard, on wry numbers like “Someone More Like You” or “If You’re Gonna Leave Me.” Fiddler Sara Watkins herself does a fair Jill Sobule on songs like the dead-on funny “Anthony,” and her brother Sean, the nimble guitarist, is no stranger to the ironic ballad either.

But I found I was just as happy when they plunged into an instrumental number, jamming away on those reels and jigs, picking and strumming with total abandon. There was even a sublime moment when Mark Schatz abandoned his acoustic bass to do a Michael Flatley bit at the edge of the stage, grinning away in his black beret and bowling shirt. I’m a sucker for that sort of genre-bending stuff; Nickel Creek delivered it all night.