Baltimore hip-hop concert promoterhas been a great asset to Sonar lately, both in bringing notable headliners to the main room and curating all-local bills on the club stage. This past Saturday's Hip-Hop for the Headstrong showcase was a prime example of the latter. And while it was a cohesive bill, featuring several acts that clearly had respect for each other, it also ended up a bit redundant, with many of the later acts blending into one another with little to distinguish from one another lyrically or aesthetically. At least the first performers, for better or worse, were able to separate themselves from the pack., a rap duo from York, Pa., were exactly as goofy and fratty as you'd expect if you've ever spent any time in Southern Pennsylvania. Thankfully, the next act stood out for all the right reasons., something of a Maryland hip-hop/R&B supergroup, featuring members of the groupsand Raw Earth, as well as singer, performed a brief set of tracks from its highly enjoyable new album,Sun Ra Used to Say. Considering that most Baltimore rappers wouldn't even know who Sun Ra is, much less name-check him in an album title, State of the Arts' live show was appropriately artsy and eccentric, with two members of the group dressing up, one wearing doctor's scrubs and the other a three-piece suit and a pith helmet. Granted, weirdo old-school-influenced hip-hop with R&B hooks and funny outfits are the kind of elements that, when mixed in the wrong ratio, could end up as something terrible like, say, the Black Eyed Peas, but State of the Arts sidestepped those dangers and walked away with the best set of the night. The later performers weren't bad per se, though. The seven-member Planet SB got the strongest crowd reaction of the night with big shout-along choruses, but they were a bit overbearing and joyless in their strident backpackerisms. The next group, Flawless, followed a similar formula to better effect, mixing dancehall-esque sung vocals with upbeat tracks that probably would've come off as reminiscent of Pharcyde even if they hadn't done a song over the beat from "Passin' Me By." But by the time rappers like J Optimo and snaPz rolled onstage to deliver more sermons on the dangers of "watered-down hip-hop" and shady industry cats, it all got to be a bit redundant. Here's hoping Steez's next local showcase features performers who are just as compatible without coming off quite so boringly homogenous.