Kechadon2000's "ja" sounds are actually "chak", which is from a Bali drama.
Kecak - Wikipedia, the free encyclopedia YouTube - hanuman chants from baraka
Awesome stuff, though.
I can pass all the 2000 songs, but so far, I can only get a full combo on Saitama "Master Notes" and Koibumi2000. I am close with Taberuna, and Soroban and Kitasaitama are the only ones that I need to warm up to pass.
Also, KitaSaitama is the first 2000 song to break the 4-syllable mold from the previous 2000 songs.