Lennon composed his 1971 song "Imagine" on the Steinway upright piano, which was purchased by pop star George Michael in 2000 for $2.1 million.
Memphis is the second stop on the tour that will include the World Trade Center in Manhattan, the bombed federal building in Oklahoma City and the Branch Davidian compound destroyed in a fiery siege in Waco, Texas.
The first tour stop was Dallas, where President Kennedy was assassinated on Nov. 22, 1963.
"This is about hopes and dreams and the world condition," Michael's partner, Kenny Goss, said Tuesday.
The Memphis stop coincides with the 39th anniversary of King's death on the balcony of the Lorraine Motel, now the visual centerpiece of the National Civil Rights Museum. King was assassinated April 4, 1968.
Goss said neither he nor Michael planned to attend.
"It would be completely distracting. What we're focusing on is the message John Lennon was trying to promote," he said.
The piano is being photographed at each site for a possible book and documentary on world peace.
LONDON - Off the cuff or up the nose? That was the question Wednesday as Keith Richards said he was joking when he described snorting his father's ashes along with a hit of cocaine.
"It was an off-the-cuff remark, a joke, and it is not true. File under April Fool's joke," said Bernard Doherty, a Rolling Stones spokesman, about Richards' quote in NME magazine.
But the magazine said on its Web site that the remark was "no quip, but came about after much thinking" by the 63-year-old guitarist.
"He didn't offer the information, I had to ask him a couple of questions to get the information out of him," said interviewer Mark Beaumont. "He didn't come straight out with that."
In the interview, Richards was quoted as saying: "The strangest thing I've tried to snort? My father. I snorted my father."
"He was cremated and I couldn't resist grinding him up with a little bit of blow. My dad wouldn't have cared ... It went down pretty well, and I'm still alive."
Richards' father, Bert, died in 2002, at 84.
In a statement posted on the Rolling Stones Web site, Richards said:
" The truth of the matter is that I planted a sturdy English Oak. I took the lid off the box of ashes and he is now growing oak trees and would love me for it!!! I was trying to say how tight Bert and I were. That tight!!! I wouldn't take cocaine at this point in my life unless I wished to commit suicide."