Former Beatles producer George Martin, the so-called 'fifth Beatle,' has died at age 90. It was announced last night by Ringo Starr on his Twitter account.

http://www.bbc.com/news/entertainment-arts-35761464

He also produced the works of such performers as America, Jeff Beck, Gary Brooker, Cheap Trick, Celiene Dion, Little River Band, and Dudley Moore. Very sad news.