Many consider Chicago to be the most successful American rock band of all time. The group formed in 1967 and consisted of Walter Parazaider, Lee Loughnane, Terry Kath, Danny Seraphin, James Pankow and Robert Lamm on organ and vocals. In December 1967, bassist/vocalist Peter Cetera joined. Chicago's first self-titled album sold more than two million copies and spawned four chart singles, beginning a string of massive hits that lasted to the end of the decade. Chicago's music was a combination of many varying styles, from hard rock to light pop and often included elements of jazz and classical. Following Cetera's gold-selling number one hit in 1976, "If You Leave Me Now," the group became more identified with romantic ballads than anything else. Chicago hit the charts again in 1982 with "Hard to Say I'm Sorry," and the million-selling Chicago 16. At the turn of the decade, Chicago Twenty 1 was released. In 1995, Chicago signed to Giant Records to release their 22nd album, Night & Day, a collection of big-band standards that made the Top 100. In 1998, they released Chicago XXV: The Christmas Album on Chicago Records, and they followed it in 1999 with Chicago 26: The Live Album. The band reappeared in 2006 with ChicagoXXX on Rhino. In 2011, Chicago released Chicago XXXIII: O Christmas Three. In 2014, Chicago XXXVI: Now arrived. The band continues to tour the world.