Boy". Described "RBB" as the sequel to their previous single "Bad Boy", "RBB (Really Bad Boy) is an "addictive" R&B and dance-pop track with "funky beat and brassy horns", which draws influence from hip-hop and jazz music. It was their sixth single to follow the "Velvet" sonic concept. With a tempo of 150 beats-per-minute, "RBB" is a fast verse-chorus form song in the key of D major. According to producer Bullock, he "wanted to create something with lots of fun energy" which made the listeners "want to move", thus using 808's for the bass of the song. The main melody was played by a trumpet and a trombone, being one of the first songs produced by Bullock to use such elements. In addition, the bridge was said to take a heavy influence on R&B and jazz music, which "would be a good contrast and add dynamics to the song", said the producer. Lyrically, the song expresses the charm of a "bad boy" that attracts the girls' attention, no matter how all the other friends say. The group's vocals span from the low note B3 to the head voice note of D6 (D7 in exclamation, being the whistle/scream note by member Irene). Furthermore, the song is heavily ornamented with melisma and vocal harmonization, all of which appeared throughout the song - from the intro to the last head run by member Wendy. Promotion and music video To promote "RBB", a video teaser containing excerpts of the song was released on November 28, 2018, 2 days before the actual release date. A day after, Red Velvet held a special V Live broadcast in which they introduced the preview of all the songs before performing a small part of the choreography for "RBB". The group then performed the song live for the first time on the music program Music Bank, an hour before the official release time. It was then followed by performances on other music programs and year-end music awards, such as Show! Music Core, Inkigayo, and The Fact Music Awards. The music video for "RBB" was choreographed by Janelle Ginestra, Kaycee Rice and Choi Sun-hee, while being directed by director Oui Kim of GDW production team. whom had previously worked with labelmate NCT on several of their releases. The "whimsical, move-infused" video features a Halloween-theme consists of a werewolf as the main protagonist - "bad boy" of the video chasing and