Nickel Creek and Fiona Apple shared the Riverside stage for just over half of last night's Milwaukee stop on what has been dubbed as Nickel Creek's "Farewell For Now Tour."

The Nickel Creek trio -- the animated Chris Thile and vocal powerhouse siblings Sean and Sara Watkins -- began the evening with mandolin / guitar duels and polite chatter; Thile getting the occasional rise from the crowd whenever he mentioned his hope for a Cubs' win.

But it wasn't until Apple coyly sauntered onto stage that the evening reached its full entertainment potential. After Nickel Creek beautifully backed her on "Extraordinary Machine," Apple found her stride, casting the initial shyness aside and -- thankfully -- putting an end to Thile's lengthy baseball rants with a sudden, "I don't give a f*ck about the Cubs!"

The audience thanked you, Ms. Apple.

The two very different dynamics -- Nickel Creek's energetic bluegrass and three-part harmonies versus Apple's intense, moody crooning -- appeared to meet happily in the middle. It quickly became apparent, however, that when Apple is on stage, she tends to become the giddy, dancing, bubbly embodiment of the spotlight. Tiny as she is, she carries with her piles of charisma, and is easily able to run the room all by her lonesome. Nickel Creek, by default, became her backing band.

The collaboration worked best, however, during the many classic country cover songs that they executed with genuine style and respect. Since neither Creek nor Apple had recently released anything -- Nickel Creek's last, "Why Should the Fire Die?" came out in 2005 and Apple's "Extraordinary Machine" in early 2006 -- the artists reveled in the opportunity to experiment and have fun. Everyone sweetly sang Gillian Welch's "I Want to Sing That Rock and Roll," but it was Apple's rendition of Pasty Cline's "Walking After Midnight" as she swished her brown cotton dress about that truly highlighted Apple as one of the great female vocalists of our time.

As Nickel Creek parts ways, Thile looks to his future as part of The Tensions Mountain Boys, as the Watkins siblings continue their Family Hour at L.A.'s Largo, where Apple is the occasional guest.