Question: What is American rock band from Chicago that formed in 1972, with Caught in the Act as a live double album?
Sentence (from "Styx (band)"): They are best known for melding the style of pop rock and hard rock with the power of a hard-rock guitar balanced with acoustic guitar, synthesizers mixed with acoustic piano, upbeat tracks with power ballads, and incorporating elements of international musical theatre.
Relevant evidence: No