Springsteen mourns E Street star

US singer Bruce Springsteen has paid tribute to keyboardist Danny Federici, a member of his E Street band, who has died of melanoma at the age of 58.

"Danny and I worked together for 40 years," he said on his website. "He was the most wonderfully fluid keyboard player and a pure natural musician.

"I loved him very much," he continued. "We grew up together."

Two Springsteen concerts scheduled to take place in Florida on Friday and Saturday have been postponed.