According to The New York Times:
The show, at the O2 arena, will be a tribute to Ahmet Ertegun, the Atlantic Records founder who died in December. The promoter, Harvey Goldsmith, said that the bill also includes Pete Townshend, Bill Wyman, Foreigner and Paolo Nutini, a 20-year-old Scottish heartthrob who was the last act Mr. Ertegun took under his wing.
“During the Zeppelin years, Ahmet Ertegun was a major foundation of solidarity and accord,” Mr. Plant said in a statement. “For us he was Atlantic Records and remained a close friend and conspirator.”