Disturbed is an American rock band from Chicago, Illinois, formed in 1996 when musicians Dan Donegan, Steve "Fuzz" Kmak, and Mike Wengren hired David Draiman  as their singer. Since the band's formation, they have sold over 11 million albums worldwide, making them one of the largest grossing rock bands in recent years. The band has released three consecutive studio albums that have debuted at number-one on the Billboard 200.

Before vocalist David Draiman joined Disturbed, they were known as Brawl, a band whose lineup consisted of vocalist Erich Awalt, guitarist Dan Donegan, drummer Mike Wengren, and bassist Steve "Fuzz" Kmak. Awalt left the band shortly after the recording of a demo tape and the other three members went on advertising for a singer. They posted an ad in the local music publication in Chicago, Illinois, called the "Illinois Entertainer". Draiman had answered the ad after going to twenty other auditions that month.

Disturbed's mascot, named "The Guy", was originally just a drawing of a face with a large grin, as seen on the back of the album The Sickness. The Guy eventually became the official mascot for the band, fully animated by Spawn creator Todd McFarlane in the album artwork and music video for Disturbed's "Land of Confusion" cover, and has also appeared on the artwork of three of Disturbed's studio albums: Ten Thousand Fists, Indestructible and Asylum.

Classified by most as a rock, or nu metal band, Disturbed is also regarded by some critics as alternative rock alternative metal, heavy metal.

Allmusic reviewer Bradley Torreano described the album Believe as "taking the sort of jump that their heroes in Soundgarden and Pantera made after their respective breakthrough records". He also described the title track as moving "from a brutal chug to a sweeping chorus that suddenly stops in its tracks and turns into a winding riff that recalls the work of vintage James Hetfield". Believe is also considered by several critics to be a step away from the nu metal sound featured on The Sickness, moving towards a more hard rock/heavy metal sound that was continued in their following albums.

According to frontman David Draiman on the band's home documentary M.O.L., the lyrics that he writes are inspired by life experience, perception, and actual experiences of his own, and he stated that he likes to present his ideas with cryptic lyrics. These lyrical themes range from the ideology of Heaven and Hell, domestic abuse, suicide, insanity, relationships, war, and Horror lyrical themes, such as vampires and demons

Guitarist Dan Donegan typically uses tunings such as drop D and drop C, which are lower tunings than regular E standard. These lower tunings allow for a darker, more mysterious feel in Donegan's riffs. Donegan also uses subtle electronic effects to add to the fullness of the music, which the rest of the band refers to as "The Dan Donegan Orchestra."