One bis.

Chicago - 25 or 6 to 4 - 7/21/1970 - Tanglewood (Official)

Chicago was an American rock band formed in Chicago in 1967.

In the beginning, they called themselves "The Big Thing" and later changed their name to "Chicago Transit Authority," which was subsequently shortened to "Chicago."

They defined themselves as a "rock and roll band with horns."

They started as a politically engaged and sometimes experimental rock band, later also exploring progressive rock and jazz rock.

In the '70s, Chicago were absolute leaders in the States for single sales, with over 40,000,000 copies sold in the USA alone, earning them 23 gold records, 18 platinum, and 8 double platinum.

Interestingly, they were also invited to the Woodstock festival. They accepted, and the band was scheduled to perform, but that scoundrel of their promoter, Bill Graham, canceled their participation to let Santana, whom he managed, play in their place.