And welcome to a special all-video edition of the round-up!

• Matt Mulholland seems to be one of more active (and talented) participants in the YouTube multi-track scene. His a cappella cover of the Ghostbusters theme made me smile.
• The Ambassadors of Harmony, on the other hand, made me miss barbershop singing. There wasn't quite this much choreography when I was doing it, though.
• Looking for a crazy hobby? How about launching anvils into the air?
• Lin-Manuel Miranda raps about Alexander Hamilton. At the White House.
• And finally, the answer to that age-old question, "How do monks who have taken a vow of silence sing Handel's Hallelujah Chorus?"