If they had only ever recorded Bohemian Rhapsody, Queen would have been assured of pop immortality. Perhaps the most opulent and outrageous hit single in history, as well as one of the longest, it combined the band’s musical talents with Freddie Mercury’s lavish operatic ambitions, but it needed the technical skills and imagination of their producer Roy Thomas Baker to bring it to fruition, not least the 160 tracks of vocal overdubs.

Baker, who has died aged 78, described the recording process in Stuart Grundy and John Tobler’s 1983 book The Record Producers. “The basic backing track was done over a two-day period,” he said. “The opera section was done over a seven-day period of at least 10 to 12 hours a day continual singing, and also continual laughing, because it was so funny to do that we were all in hysterics while it was being recorded. Then there were all the guitar overdubs and getting on for two days to mix it. I’d say that track, on its own, took … three weeks, because it’s three songs merged together to make up this one track.”

It gave Queen a UK No 1 hit and also topped charts around the world, despite the fact that their record label, EMI, initially refused to release it as a single because, at nearly six minutes, it was deemed to be too long. Luckily the band had a keen supporter in the Capital Radio DJ Kenny Everett. Baker slipped him a copy of the song, and Everett ignored orders from above not to play it, giving it 14 spins over a single weekend. This generated a stampede of listeners trying to buy it, prompting EMI to change its mind.

The song was later declared the UK’s biggest-selling single of the 70s. It topped the UK charts again in 1991, when it was reissued as a charity single after Mercury’s Aids-related death. In 1992 it reached No 2 in the US after being featured in the film Wayne’s World.

Baker produced five albums with Queen, his last in 1978, but his work with them was merely one aspect of a rich and varied career. He also enjoyed substantial success with the Boston-based band the Cars, whom he began working with after watching them at a college gig during a ferocious blizzard. “Even though a lot of other producers and record executives from various companies had been to see them, nobody seemed to have quite seen their potential,” he pondered.

He took them to London and recorded their debut album at Air Studios, which went on to sell 6m copies in the US. He was especially pleased with the track Good Times Roll, where he added Queen-style massed harmonies to a minimal backing track. “I was able to put big vocals on a sparse, punkish background, sort of inventing post-punk pop,” he said. He went on to produce three more US top 10 albums for them. The Cars’ vocalist and songwriter Ric Ocasek saw Baker as “an electronics whiz, a sound guy with a classical background for mic-ing the room’s sound”, adding that “he got harmony – and he took things in his stride – a very upbeat, elegant man. Spontaneous, too.”

Other clients who benefited from Baker’s expertise included Man, Lindisfarne, Be-Bop Deluxe, Ron Wood, Ian Hunter, the heavy metal band Lone Star and the Scottish band Pilot, with whom he recorded the album Morin Heights (1976). “It was a great album with some really good tracks,” he said of the latter. “It’s probably one of the best I’ve ever done, but very few people know it exists.”

He also produced Dusty Springfield’s album It Begins Again and Journey’s multi-platinum success Infinity in 1978, while the following year he helped create Foreigner’s US No 5 hit album Head Games, also enjoying another smash album hit with Journey’s Evolution. T’Pau’s album Bridge of Spies (1987) topped the UK charts and delivered a slew of hit singles including China in Your Hand, a UK No 1. Ozzy Osbourne’s Baker-produced No Rest for the Wicked hit the US Top 20 in 1988, and Smashing Pumpkins’ Zeitgeist was a Top 5 hit album in the US and the UK. In the mid-80s Baker became an A&R executive at Elektra Records in the US and oversaw signings of artists including Metallica, Simply Red and 10,000 Maniacs.

He was born in Hampstead, north London, where he settled from an early age on the idea of becoming a record producer. “Between the ages of eight and 12 was when I decided,” he recalled. “I wasn’t so much listening to productions as intrigued by sound.”

He left school at 16 and was hired as an assistant engineer by Decca in 1963. He initially worked on classical recordings, including with the D’Oyly Carte Opera Company, then made the switch to rock’n’roll, working on some Billy Fury tracks at West Hampstead studios. He was employed as second engineer to producers such as Gus Dudgeon and Tony Visconti, and worked on records by artists including the Rolling Stones, Ten Years After, Dr John and the Moody Blues. He engineered Free’s worldwide hit All Right Now and T Rex’s breakthrough single, Ride a White Swan.

Baker’s big step up to producing came courtesy of Nazareth. He had engineered their first album, Nazareth (1971), after which the band invited him to produce the follow-up, Exercises (1972). Having left Decca he was by now signed independently to Trident Studios, and one of his partners at Trident, John Anthony, suggested he should visit the new De Lane Lea studio in Wembley to hear an unknown band who were making some demo recordings there. The group were about to name themselves Queen, and Baker recalled how “I walked in and they were doing a demo of a song called Keep Yourself Alive, and I said I thought it was fabulous and wonderful.”

He persuaded Trident to sign Queen to a recording, publishing and management deal with its offshoot record production company, Neptune Productions, in 1972, and then set about producing their debut album, Queen, released in 1973. It reached No 24 on the UK charts, but the group fared much better with Queen 2 (1974), which reached No 5 in the UK and pierced the US top 50.

Baker was at the controls for Sheer Heart Attack (1974), which reached No 2 in Britain and No 12 in the US, and spun off a major international hit single with Killer Queen. Then came A Night at the Opera (1975), which contained Bohemian Rhapsody, a complete one-off. “The thing that makes it most ageless is the fact that it didn’t confine itself to any given genre of music,” Baker said. “It doesn’t compete with anything – it’s in a world of its own.”

He is survived by his wife, the actor Tere Livrano, and his brother Alan.

• Roy Thomas Baker, record producer, songwriter and arranger, born 10 November 1946; died 12 April 2025