Vulfpeck are officially part of the funk A-list. The credits to their spastic third full-length LP, Mr. Finish Line, are just as elite as the grooves. Funkadelic bassist/singer-songwriter Bootsy Collins appears on the adorably goofy “Captain Hook,” and two of soul music’s most iconic session players—drummer James Gadson and guitarist David T. Walker—assist on the suave ballad “Grandma.” Given the quartet’s elite chops, it was only a matter of time. Ever since their viral video breakout in 2011, these onetime Michigan music students have gained traction—and famous fans—with each album, marketing stunt (their silent Spotify release, Sleepify, which funded an entire admission-free tour) and lo-fi YouTube clip. Here’s the rub: Vulfpeck are so damn funky on their own that these cameos often feel like unnecessary muscle-flexing or name-dropping, a distraction from the joyous grooves everyone came to hear in the first place. Mr. Finish Line relies too heavily on guest vocalists, famous or not—like Coco O.’s bland crooning on “Business Casual,” which suggests The Jackson Five on Mars, or Charles Jones’ overwrought belting on “Baby I Don’t Know Oh Oh,” a not-so-distant cousin of “Bennie and the Jets.” Vulfpeck clearly relish the thrill of collaboration, but their songs are better without it. When these dudes let loose instrumentally, like on the disco-jazz rave-up “Tee Time” or the dirty 1970s sitcom-theme strut of “Hero Town,” they reach a peerless funk plane.