From Halopedia, the Halo wiki
Flip music is a genre of music created and performed by humans.
The "slam-bam" beat of flip music is descended from 21st century heavy metal. By the 2520s, flip music was popular at dance clubs, which are common destinations for Marines and Orbital Drop Shock Troopers on leave. Avery Johnson had an odd fascination with the genre. Many people dislike flip music, including Captain Jacob Keyes, SPARTAN John-117, Corporal Locklear, Private First Class Wallace Jenkins, and Privates Riley, Mendoza, and Bisenti.
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