Rock and Roll Hall of Famer Johnnie Johnson [ tickets ], who played piano on many of Chuck Berry [ tickets ]'s best-known songs and is considered a key architect of Berry's sound, died Wednesday (4/13) at his St. Louis home. He was 80.

The cause of death wasn't immediately known, but Johnson reportedly had been hospitalized last month with pneumonia and was on dialysis, according to published reports.

The Berry song "Johnnie B. Goode" was a tribute to Johnson. Though Berry retains the songwriting credits on his hits, he often converted Johnson's piano music to guitar, and added lyrics; a 2000 lawsuit in which Johnson attempted to gain a portion of the royalties was thrown out of court due to the age of the dispute.

Bob Dylan and Los Lonely Boys will join Willie Nelson [ tickets ] for his 32nd annual Forth of July Picnic, set to take place in Fort Worth, TX. About 20 additional acts will be announced, according to organizers.

50 Cent [ tickets ]'s "The Massacre" again is the top-selling album in the U.S., extending the rapper's chart reign to six straight weeks. Faith Evans' "The First Lady" enters The Billboard 200 chart at No. 2.

Beck's "Guero" slips one spot to No. 3, while the hits compilation "NOW That's What I Call Music! Vol. 18" moves from No. 4 to No. 5. Rounding out the Top 5 is 112's "Pleasure & Pain," down from No. 4 a week ago.

After a month-long stay at a Southern California rehabilitation center for treatment of alcohol abuse, Billy Joel [ tickets ] reportedly checked out on Sunday (4/9).