On this date in 1970, the Mac lost its original guitarist, Peter Green, but he left the band on his own, announcing he had found God. 
Other April 11th comings and goings... 19 year-old Bob Dylan makes his concert debut in an appearance with John Lee Hooker (1961) … Metallica fires Dave Mustaine, replacing him with Kirk Hammett (1983), Dave Prater of Sam & Dave killed in a car wreck (1983), John "Jay" Geils of the J Geils Band dies (2017).

On April 11, 1988, Neil Young released This Note's For You, the album with a title song that made his case against commercial endorsements and sponsorships.