Muhl is a singer/songwriter and also a multi-instrumentalist, with the instruments she plays including, guitar, bass, keyboard, and the bayan. Lennon and Muhl are involved in a musical project, titled "The Ghost of a Saber Tooth Tiger". The couple also formed the record company "Chimera Music". Muhl has another musical project with longtime friend Eden Rice, called "Kemp and Eden." Muhl and Eden signed to independent labelRiver Jones Music and released the LP Black Lace Hole in 2012. Muhl stated on a number of occasions that she uses funds earned from her lucrative modeling career to produce her music. In 2017, Muhl founded the band Uni, with vocalist Nico Fuzz and guitarist David Strange. On November 17, 2017, they released their debut 7" single What's the Problem b/w Adult Video. Each song received the music video treatment, both directed by Muhl. The band's next release is the "Mushroom Cloud" 7", out March 23, 2018.
In 2005, she appeared briefly as Steven Tyler’s love interest in Carlos Santana’s video for Just Feel Better
Starred as Lola in Elefant's Lolita music video
Appeared in Young Love's "Find A New Way " music video
Music videos directed
Directed and appeared in Jesse Harris's "Borne Away" music video. Charlotte sang background vocals as well.
Directed and appeared in David Strange's "Aztec Corn" music video
Directed and appeared in David Strange's "Vitamin Pills" music video
Directed David Strange's "Cocaine" music video
Directed David Strange's "Mean World" music video
Directed David Strange's "Lion Tattoo" music video
Also produced, arranged, played drums, and sang background vocals on David Strange's 2015 EP.
Directed Invisible Familiars' "Act One" music video
Directed The Moonlandingz' "Black Hanz" music video
Directed Mark Stoermer's "Blood and Guts" music video
Directed Uni's "What's The Problem?" music video
Directed Uni's "Adult Video" music video
Personal life
Muhl met Sean Lennon, at the Coachella Valley Music and Arts Festival, in 2005 and since then, the two have been in a relationship since 2007. In an interview, Lennon states he stumbled upon Muhl's musical talents over a year after they had started dating. Muhl and Lennon are involved in a number of musical endeavours, and much of their work is written at their own home-based studio in Greenwich Village.