Lunar,
No pun attended, it really shows that singing in a duet is not that easy, as it sounds. That 3min song, could take much a longer time to do, or a 2min song could be done very quickly. Yeah, its true when the BGM comes up my voice is too low or out of snyc; which I don't 100% like. The process, is probably not fun, but once its done, onto the next song.
MW