What’s a young bluegrass star with pop inclinations to do? In the case of Sara Watkins, singer and fiddler in the immensely popular crossover group Nickel Creek, you call in your friends. Watkins’ lovely self-titled solo debut is graced with guest turns by not only her Nickel Creek bandmates Chris Thile and Sean Watkins (her brother), but also Gillian Welch and David Rawlings, keyboardist Benmount Tench (of Tom Petty’s Heartbreakers), pedal steel ace Greg Leisz and Elvis Costello drummer Pete Thomas — not to mention some producer by the name of John Paul Jones (yeah, the Led Zeppelin guy, who also played with Watkins in the Mutual Admiration Society). Throw in smartly chosen covers by Norman Blake, John Hartford, Jon Brion and Tom Waits, and you’ve got the perfect showcase for Watkins’ crystalline vocals and sizzling fiddle leads. She may have been the last member of Nickel Creek to take a solo dip, but she’s off to an ultra-assured and beautiful start.