They called him the fifth Beatle on the radio station I heard the announcement on. I recall reading how he had a calming affect on the Beatles when he was invited to sit in during some of their later sessions.
Billy Preston Dies
I hadn't realized he'd been in a coma since last November with kidney failure. Here's a link to the Washington Post article. (For some reason it neglects to mention his other big hit single of the 70's as a solo artist, "Will It Go 'Round In Circles"). Although I can't say I'm a big fan of his own albums aside from the hit singles, Preston was an amazingly talented and natural musician, famously a teenage prodigy on piano and organ, who always complemented and heightened the impact of other artists' work with whom he guested. And he seemed to radiate an infectious cheer and good will in his public persona like few others in rock, even though he clearly had his private demons. A sad day, music lost a truly beautiful cat.