Of her next “Rock It Properly” broadcast (tonight at 8pm), host DJ Darla Bea writes: “Tonight’s two-hour program will present a lesson on vocal groups, a cappella pop, barber-shop quartets, harmonizing singers, and doo-wop groups.

Tune in tonight and get ready to rock — in perfect harmony!”

“Rock It Properly” airs on Sundays in the winter from 8-10pm PST.