The topic is Barbershop music, kinda like rap and stuff like that. 
I think Barbershop music is so beautiful.  The harmonies are so pretty!
Jimmy Fallon does them on his show every once in a while, Have you ever seen any of them?
Barbershop music
Barbershop vocal harmony, as codified during the barbershop revival era (1930s–present), is a style of a cappella close harmony, or unaccompanied vocal music, characterized by consonant four-part chords for every melody note in a predominantly homophonic texture. Each of the four parts has its own role: generally, the lead sings the melody, the tenor harmonizes above the melody, the bass sings the lowest harmonizing notes, and the baritone completes the chord, usually below the lead. The melody is not
their victims. In one of the tapes, Ng is seen telling victim Brenda O'Connor, "You can cry and stuff, like the rest of them, but it won't do any good. We are pretty ... cold-hearted, so to speak." In the other, Deborah Dubs is shown being assaulted so severely that she "could not have survived".
Ng, meanwhile, had fled to Calgary, Alberta, Canada, where his sister resided. He lived, undetected, in a lean