AAlthough they began as an artsy prog rock band, Styx would eventually transform into the virtual arena rock prototype by the late '70s and early '80s, due to a fondness for bombastic rockers and soaring power ballads. The seeds for the band were planted in another Chicago band during the late '60s, the Tradewinds, which featured brothers Chuck and John Panozzo (who played bass and drums, respectively), as well as acquaintance Dennis DeYoung (vocals, keyboards). By the dawn of the '70s, the group had changed its name to TW4, and welcomed aboard a pair of guitarists/vocalists, James "JY" Young and John Curulewski - securing a recording contract in 1972 with Wooden Nickel Records (a subsidiary of RCA). Soon after, the group opted to change its name once more, this time to Styx, named after a river from Greek mythology that ran through "the land of the dead" in the underworld.

They are best known for melding hard rock guitar balanced with acoustic guitar, synthesizers mixed with acoustic piano, upbeat tracks with power ballads, and incorporating elements of international musical theatre. The band established itself with a progressive rock sound in the 1970s, and began to incorporate pop rock and soft rock elements in the 1980s.