Majima looks momentarily taken-aback my Amelia's lack of familiarity, then remembers Nexus. Of course. Not everyone has the same cultural touchstones.

"Karaoke? Right." He scratches the back of his head. "So, uh, back in Japan, lotsa bars have these machines full'a songs and screens that show you the lyrics. Ya pick out a song, and do yer best to sing it. Pretty simple."

His response to Harley's invitation is to draw her out of the kitchen. He calls back to Amelia, "If ya got a good set of pipes on ya, or you've had enough to drink, ya won't be embarrassed at all!"