Charlie Rosen is an American musician, composer, arranger, orchestrator, musical director, and music producer. He is best known for his work on Broadway, where he has worked on Be More Chill, Prince of Broadway, American Psycho, and, along with Bryan Carter, won the 2023 Tony Award for Best Orchestrations for Some Like It Hot. He is also the leader of the 8-Bit Big Band, a jazz orchestra specializing in video game music.

Be More Chill is a musical with original music and lyrics by Joe Iconis, and a book by Joe Tracz, based on the 2004 novel of the same name by Ned Vizzini. After a 2015 regional theatre production, the musical premiered off-Broadway in 2018. A Broadway production began previews on February 13, 2019, and officially opened on March 10, 2019. The Broadway production closed on August 11, 2019. An Off West End production opened on February 18, 2020, and temporarily closed on March 16, 2020, due to the ongoing COVID-19 pandemic with the production being cancelled on June 3, 2020. In 2021, it was announced that the production, featuring the original London cast, would resume performances on the West End at the Shaftesbury Theatre for a 10-week run starting June 30. A Chicago production was set to open in July 2020.