Danny Federici, a keyboardist for Bruce Springsteen’s E Street Band since it was formed in the early 1970s, died on Thursday. He was 58 and lived in Manhattan.

His death, at Memorial Sloan-Kettering Cancer Center in Manhattan, was caused by melanoma, according to Mr. Springsteen’s Web site,brucespringsteen.net.

Mr. Federici was Mr. Springsteen’s collaborator since they jammed together at clubs on the New Jersey shore in the 1960s. “He was the most wonderfully fluid keyboard player and a pure, natural musician,” Mr. Springsteen said in a statement. “I loved him very much. We grew up together.”

Born in Flemington, N.J., Mr. Federici began studying classical accordion at 7 before switching to electric organ and joining rock bands. He played at clubs in Asbury Park and made his first recording on a single by an Asbury Park songwriter, Bill Chinnock, whose bands included two other future members of the E Street Band: Vini Lopez on drums and Garry Tallent on bass.

Mr. Federici and Mr. Lopez started their own band and invited Mr. Springsteen to become a member. “This skinny guy with long hair and a ratty T-shirt was an incredible guitar player and a good singer, so we asked him to join,” Mr. Federici once said.

The band was named Child and soon renamed Steel Mill, which built a strong reputation touring the East Coast. Mr. Federici was also in Mr. Springsteen’s short-lived band Dr. Zoom and the Sonic Boom.

He did not play on Mr. Springsteen’s debut album, “Greetings From Asbury Park, N.J.,” from 1973, but he was in E Street when Mr. Springsteen introduced the band that year on “The Wild, the Innocent and the E Street Shuffle.”

Mr. Federici remained in every E Street Band lineup, along with Mr. Tallent on bass and Clarence Clemons on saxophone, until taking a medical leave of absence in November 2007. Mr. Springsteen called him “one of the pillars of our sound.”

Like a gospel group, the E Street Band includes two keyboardists, one usually playing piano and the other an organ. Mr. Federici, whom Mr. Springsteen often introduced as “Phantom Dan,” was the organist; he also played accordion for songs like “4th of July, Asbury Park (Sandy).” His role in the band was most often supportive, filling out the harmony with beefy chords from his Hammond B-3 organ.

But Mr. Federici is in the foreground with the organ solo on the 1980 hit “Hungry Heart.” At times, to give the E Street Band its chiming, Phil Spector sound onstage, he played a keyboard-operated glockenspiel, one of few in existence.

For much of the 1980s Mr. Springsteen kept the E Street Band on retainer while working with other musicians. Mr. Federici played on Mr. Springsteen’s 1987 solo album, “Tunnel of Love,” and was a member of its touring band. He was a studio musician on Mr. Springsteen’s 1995 solo album, “The Ghost of Tom Joad.” Through the years he played recording sessions for Joan Armatrading, Garland Jeffreys, Graham Parker and Little Steven and the Disciples of Soul, among others.

Mr. Springsteen reconvened the E Street Band to record new songs on a greatest-hits album in 1995 and started touring with it again in 1999. “The Rising,” Mr. Springsteen’s 2002 record, was his first full album with the E Street Band since “Born in the U.S.A.” in 1984. They have toured together often since its release.

Mr. Federici, whose replacement after November 2007 was Charles Giordano, last performed with Mr. Springsteen and the band onstage in Indianapolis on March 20. They are still on tour, but have postponed some shows.

Between E Street Band engagements, Mr. Federici led his own groups in clubs and released two albums of pop-jazz: “Flemington” in 1997 (reissued as “Danny Federici” in 2001) and “Sweet” in 2004 (reissued as “Out of a Dream” in 2005).

He is survived by his wife, Maya; his son, Jason; and his daughters Madison and Harley.