Here are some comparison pictures of season 2 (left) and season 1 (right).
In other Symphogear G news the first character song CD has a store listing on Rakuten that confirms it will only be 1 song (instead of 2 like in season 1), this explains the very cheap price of 800 yen (about $8). The interesting thing is that there is a TV Size version included! This is usually only done if a song is cut for TV as an Opening or Ending song...so it's possible that this character song might be used like that for Symphogear G. We'll have to wait to find out for sure, though.
Also Nana Mizuki recently posted on her blog saying she completed a recording session for one of Tsubasa's character songs in Symphogear G. She mentioned that this particular song has a very quick tempo, with a wide singing range and a difficulty level of 3 stars for her. She also said that she feels there will be a lot of concert songs and battle songs in season 2, so everybody should look forward to it!
On twitter, Agematsu said that recently the music recording for Symphogear G has also started by which I'm assuming he means the OST recording (since the character songs CDs have already started recording). Anyway, from everything that's been said it seems we can look forward to even more powerful and hyped up singing and fighting than before! Get hype!