On this day, December 1st, in 1975 Chicago rock band Styx released their fifth studio album ‘Equinox’ via A&M Records. ‘Equinox’ was the last album in the band’s discography to have  John Curulewski as an active guitarist, but he was quickly replaced by current member Tommy Shaw. The album itself was mediocre but did manage pretty well in the long run with the album peaking at number 58 on the Billboard 200. The album would also become certified Gold by the RIAA in 1977. Listen to the album below!