Talking about BGM, while I am not one to play the game with music on (usually have youtube or some other thing playing in the background), but I do recall Girls Symphony had amazing BGM. Huuuuu ~ cant wait for that game to finally launch !
(my guess is the beginning of 2019 ? I expected it to be online already, but they are still doing the pre-reg, even increased the number of characters you can get from the gacha from one to 2).