Bang! may seem a little too chant-y for my taste, but I like it because it really works for After School. They're not a band that can pull off very vocally-demanding songs, but they're not a band with absolutely no vocal ability either. The melody is simple enough to sing by decent voices and it would sound good, but it has enough spunk to pass for a lead single.
The very hard and sometimes soul-less drum rolls throughout the song make the melody simpler, actually. The "sonic mess" I was talking about earlier this year isn't really a mess - it reminds me a lot of DBSK's O Jung Ban Hap and how this super dance-y and intense song turns into a puddle of gorgeousness. Of course DBSK can pull that off effortlessly and they have the production team to do it while After School/Gahee struggled and they don't exactly have a Yoo Young Jin to whip their songs into shape, but it was a good try.
Speaking of production, I never said it, but Bang! has some of the best non-SM production this year and is probably as good as Kara's Jumping. Plus the fact that After School have more gutsy and generally better vocals than Kara. Why do I find myself comparing everyone to Kara these days?
Speaking of vocals, I'd like to point out the performance where I found out that Lizzy actually has a voice, that I have a love-hate relationship with Raina's voice, that Gahee is one of the stronger singers, and that Jung Ah is obviously my favorite voice in the band. Even with the crap sound system and non-existent acoustics, this was by far the best performance of Bang!. It was also the last one I recapped, if I'm not mistaken.