Glitter, Go-Gos and a goth Quinn - Teaser trailer promises big changes for 'Glee' (VIDEO)

Even with all the backstage firing/hiring/general mayhem that happened this summer, Glee's new teaser trailer helps remind fans why the Fox musical dramedy is nothing short of a phenomenon.

It may only be 30 seconds long, but that's half a minute for Gleeks to get a sneak peak at a peppy new tune, a possible relationship upgrade for Will and Emma, and a punky Quinn.

The video features some staple McKinley High shenanigans -- a slushie to Finn's (Cory Monteith) face, Brittany (Heather Morris) and Santana (Naya Rivera) prancing around in Cheerios uniforms, and the glee club doing their darnedest to get the school riled up with a hand-clapping rendition of the Go-Go's "We Got the Beat."

Aside from the "glitter bomb" dumped on Sue Sylvester (Jane Lynch), two other things seem to flash out at fans.

One, Quinn's (Dianna Argon) apparent transition from prep to pink punk. According to MTV, the actress took to Twitter to explain her bubblegum locks, promising the coloring was for work, but that's all she would say, not wanting to give away any plot details.

Secondly, The Huffington Post points out the blink-and-you'll-miss-it shot of last season's breakout star Darren Criss performing with the rest of New Directions, implying that Blaine's transfer from the rival school to McKinley is imminent.

Feel free to go ahead and obsessively mull over the clip's details below, and mark your calendar for September 20.