Nickel Creek has never been traditional. While its hybrid brand of bluegrass is rooted in acoustic stylings and fierce virtuosity, covers of new rock hits — from Pavement, Radiohead and Britney Spears — place the group far from the likes of twang greats like Bill Monroe. But in the best of ways.

Now at a time when even the Spice Girls have decided to jump on the reunion-tour bandwagon, the Grammy-winning So Cal trio is again going against the grain. Nickel Creek’s gently placing the fiddle down and celebrating its last days together — for now anyway — with a unique farewell tour.

Vocalist and mandolinist extraordinaire Chris Thile says that the show will be chock-full of surprises and appearances by familiar names, including, on some dates, Glen Phillips, Mark Schatz and, most notably, wistful singer-songwriter Fiona Apple.

While Thile says he doesn’t know Apple well, aside from playing together a few times, he’s humbled in the presence of someone he “respects very much as a musician.” She is, he adds with a laugh, “a big deal that will make us look really cool when we roll into town with multiple tour buses.”

The pairing of the unlikely duo actually stems from a longtime friendship between Apple and Nickel Creek’s Sean and Sarah Watkins, siblings who began jamming together at the renowned club Largo in Los Angeles. Audiences can expect to hear equal amounts of material from Nickel Creek and Apple, as well as a handful of collaborations. A real twist on Apple’s piano-centric songs will come as she relies on Nickel Creek for backup during her set.

All the members of Nickel Creek have new musical ventures in sight, and Thile eagerly offers up details about his new band, The Tensions Mountain Boys. With a new CD in the works and a soft spot for Richmond’s distinctive architecture, Shockoe Bottom and kind people, the string picker promises that fans will get to see at least one-third of Nickel Creek in the near future. For now, they can bid Thile and company adieu at what promises to be one of the summer’s most memorable gigs. S

Nickel Creek and Fiona Apple play Innsbrook After Hours Friday, Aug. 3, at 6 p.m. Tickets are $20-$40. Call 423-6589 or visit www.innsbrookafterhours.com.