John Lodge, the singer and bass guitarist for the British rock group the Moody Blues, who wrote some of the band’s biggest hits, including “Ride My See-Saw” and “I’m Just a Singer (in a Rock and Roll Band),” has died. He was 82.

His family confirmed the death in a statement on Friday, but did not cite a cause or say where or when he died. The statement said that Mr. Lodge “has been suddenly and unexpectedly taken from us.”

The Moody Blues formed in 1964 and released their first album, “The Magnificent Moodies,” in 1965. Mr. Lodge and the guitarist and singer Justin Hayward joined later, replacing Denny Laine and Clint Warwick to round out a lineup that also featured Mike Pinder on keyboards, Graeme Edge on drums and Ray Thomas on flute and vocals.

While the group’s repertoire originally consisted largely of R&B covers, the Moody Blues became a pioneer of the progressive rock movement during the late 1960s and early ’70s.

Their 1967 album, “Days of Future Passed,” is considered a progressive and psychedelic rock landmark, featuring elaborate arrangements rounded out by contributions from the London Festival Orchestra. “In Search of the Lost Chord,” which was released in 1968 and featured Mr. Lodge’s propulsive “Ride My See-Saw,” leaned more heavily on the Mellotron, an electromechanical keyboard that plays samples of different instruments.

In 2018, the Moody Blues were inducted into the Rock & Roll Hall of Fame and performed one of their signature songs, “Nights in White Satin,” which Mr. Heyward wrote for “Days of Future Passed.”

At the ceremony, Mr. Lodge said in a speech that the album “changed our lives forever.”

John Lodge was born in Birmingham, England, on July 20, 1943. He bought his first bass, a Fender Precision model with a sunburst finish, at age 16. Mr. Lodge would later use the instrument to record music for the Moody Blues, according to a biography page on his website.

When he was in school, he and Mr. Thomas formed a band called El Riot & the Rebels.

Mr. Lodge’s survivors include his wife, Kirsten; a son, Kristian; a daughter, Emily; and a grandson.

Mr. Pinder, the last surviving founding member of the Moody Blues, died in 2024.

After the Moody Blues stopped touring in 2019, Mr. Lodge continued to perform live, including with his son-in-law Jon Davison, a member of the current lineup of the progressive band Yes.

In recent years, Mr. Lodge released “Days of Future Passed — My Sojourn,” a recording that he said represented his “reimagining” of the group’s most famous album.

Last summer, he toured in the United States, including stops in Illinois and in New Jersey, with a show titled “Singer in a Rock and Roll Band.”

An expanded obituary will appear later.