Can someone explain this sentence to me? なに言っちゃってんの！？　この曲の良さがわがんないわけ！？ Basically, I understand the first half. I just don't understand the whole bunch of hiraganas close to the end. Can someone sperate the hiragana "さがわがんないわけ" for me? I don't know which one of them form a word of the whole as a word. Thanks a lot!