This is a big day in rock and roll history, and Chicago plays a role in it. I didn't know this story, featured today in Bob Dearborn's The Olde Disc Jockey's Almanac...
"May 10, 1965…At Chess Studios in Chicago, the Rolling Stones recorded "(I Can't Get No) Satisfaction," a version featuring Brian Jones on harmonica. The band re-recorded it two days later in Hollywood, with a different beat and a Gibson Maestro fuzzbox added to sustain the sound of the guitar riff. It was the May 12 Hollywood version that was released. Newsweek later called the opening riff "five notes that shook the world."