And so what is likely the last video off Katy Perry's indomitable Teenage Dream arrives — mouth gear, continuity issues, Rebecca Black, and all. As has been teased pretty hard for the past few weeks, in the video for Song of Summer contender "Last Friday Night (TGIF)," Perry plays Kathy Beth Terry, a nerd in the Sixteen Candles mold who has huge glasses, a brace face, and just threw a rager. Perry continues to prove herself to be an ace nostalgist, making the whole thing an extended homage to an eighties teen movie, with dozens of anachronistic flourishes (in this eighties movie, all the morning-after pictures end up on the Internet) and celebrity cameos. Darren Criss is the sweet kid who tells Perry the party is great; Black is her helpful, socially adept friend; Glee's Kevin McHale is her fellow metal mouth and true love interest who eventually defeats the ripped, asshole jock; Hanson plays the party; Debbie Gibson (sorry, no Deborah) and Corey Feldman (enjoying himself to much) show up as Perry's parents; and Kenny G performs the song's triumphant sax solo from the roof of the garage. Though Perry has a difficult time looking like she's really singing because she's so focused on appearing to have an overbite, she's working hard here, and in strident good humor. She does manage to sneak in some trademark lewdness — at one point, she eats a banana! And, also, there are always the lyrics— but when it comes to makeover time, she doesn't emerge as just the hot girl. She's still all gangly next to ... Rebecca Black. Perry's kindness to Black is the good-vibe engine of this whole production: In the video, Black helps Kathy Beth Terry to be cool (by giving her makeup and fake boobs, and waxing her totally nonexistent mustache), but in real life, Perry's doing the solid for Black, who seems orders of magnitude less awkward than she did in the viral video for "Friday." Whatever you think of Black or Perry, amid all the roller skates, silly string, and video-game product placement, the latter's certainly trying to do a branding mitzvah for the former. If that means we'll have Rebecca Black to kick around for a few more months, well, at least now we know she can do a pretty mean robot.