Robin Hannibal and Coco of Quadron** **Not their actual size.Quadron kicked off my third and final day of Bumbershoot with a sweet performance at the Fountain Lawn stage; vocalist Coco and producer Robin Hannibal were joined onstage by a drummer who kept time to the duo’s harmonized hums and syncopated finger snaps. Coco is the star of the Quadron show–she has a beautifully velvety voice, she wore a shiny dress patterned with glinting rainbow confetti that won best outfit at Bumbershoot in my book, and she is absolutely charming–her genuine surprise when someone in the audience knew her name was touching. Set highlights were the sleek “Buster Keaton,” the flouncing single “Pressure” (“This song was written about my sister,” said Coco, and when the audience aww’ed, “No, it’s not even that cute. It’s actually kind of mean.” Look up the lyrics and you’ll see what she means), and best of all, their tender-but-sultry cover of Michael Jackson’s “Baby Be Mine.” Quadron’s got some tightening of loose ends to tend to, but with some more polish I could easily see them playing for a mainstage-sized audience.The last set of the day that I caught was another highlight–Phantogram, also on the Fountain Lawn stage. I’ve seen Phantogram a few times–each time they’ve been awesome–but last night was the first time I’ve seen Sarah Barthel come out from behind her keyboard to sing; she also took more liberties with her vocals on songs like “As Far As I Can See.” (The way that Phantogram’s set has evolved into something so suave and sharp is actually a good example of where a greener band like Quadron could end up eventually.) Barthel’s bandmate Josh Carter also interacted more with the audience, who are all digging pretty hard on Phantogram’s thudding beats. “Y’all know how to bounce,” Carter said at one point, which is not something people in Seattle hear a lot. “Mouthful of Diamonds” was sublime, as was the union of ghostly vocal melodies over the thick bass line of “Running From the Cops.” But it’s been some time since Eyelid Movies–one of my favorite albums of 2010–came out, so it was nice to hear three new songs, including one steady pulser called “Don’t Move.” Some other Monday notables: Hearing the phrase, “I don’t know, he broke a table or something,” from a friend referring to one Eric Grandy when asked about last night’s After Dark Rave. One of Bumbershoot’s best bookings in recent memory, Big Boi’s afternoon Key Arena set was woefully underattended. (He still killed it). Dom’s lead singer, Dom, was in a cranky mood, but their set of sparkling, high-pitched pop-rock still went off nicely and included an exuberant cover of “Boys Don’t Cry.” Noelle Scaggs of Fitz and the Tantrums , whose yellow blazer matched her yellow tambourine, is a wonder–someone needs to get that girl to center stage instead of relegating her to the sideline. But Fitz founder Michael Fitzpatrick is a little one-dimensional as a frontman, and after hearing a couple songs, I can’t imagine their second album sounding any different than their first.Follow us on Facebook and Twitter.