The guitarist and songwriter John Sykes, who has died of cancer aged 65, was best known for his work with the erstwhile Deep Purple vocalist David Coverdale’s band Whitesnake, with whom he made his stage debut in Dublin on 17 February 1984. Sykes added guitar parts for a new version of the band’s album Slide It In (1984), aimed specifically at an American audience; the album sold 6m copies worldwide.

He was then integral to the band’s next album, 1987 (called simply Whitesnake in the US), on which he co-wrote virtually all the songs with Coverdale, and also worked with the sound engineer Bob Rock to create the specific guitar sound he wanted. It worked, and 1987 eventually sold 25m copies. Boosted by heavy MTV airplay of the single Still of the Night, it reached No 2 on the US album chart, Whitesnake’s best US chart showing, and No 8 in the UK. With his tumbling blond hair and boyband good looks, Sykes was perfectly suited to what became known as “hair metal”.

However, commercial success was not accompanied by harmonious personal relationships, and the Coverdale-Sykes combination did not last. Indeed, by the time the album was released, all the band members had been replaced by new signings. Coverdale later commented that “John was and is an incredible talent. Our musical chemistry was great, but it didn’t work personally … We were unable to connect as people.”

Sykes made little secret of his bitterness at being sacked, but he then formed the trio Blue Murder, with the bass player Tony Franklin and the drummer Carmine Appice. They released a self-titled debut album in April 1989, and toured Japan and the US. The album would sell half a million copies, but both the band and their record label, Geffen, were disappointed that it had underperformed. A disgruntled Sykes said: “In hindsight, I would have done better with a different label.”

Personnel problems also plagued Blue Murder. By the time they made a second album, Nothin’ But Trouble (1993), Franklin and Appice had been replaced by Marco Mendoza and Tommy O’Steen, though Appice and Franklin played on the disc as hired session men. Despite some good reviews, the album sold poorly, Sykes again blaming the record label for failing to promote it. Blue Murder’s final release was the live album Screaming Blue Murder: Dedicated to Phil Lynott (1994).

In 1994 Sykes finally parted company with Geffen, and released a string of solo albums on the Mercury Japan label – Out of My Tree (1995), Loveland (1997), 20th Century (1997) and Nuclear Cowboy (2004). His final album release was Bad Boy Live! (2004), on the Victor label.

John was born in Reading, and spent several years living in Ibiza where his father and uncle owned a discotheque. While there, he began learning guitar, at first playing on a nylon-stringed acoustic instrument. He began to turn professional in the late 1970s, after he had moved to Blackpool and was asked to join Streetfighter, a Rolling Stones tribute band. Sykes’s playing could be heard on Streetfighter’s song She’s No Angel, which featured on the album New Electric Warriors (1980), a compilation of tracks representing the so-called new wave of British heavy metal.

He then joined Tygers of Pan Tang, a metal band formed in Whitley Bay, and stayed with them while they recorded the albums Spellbound and Crazy Nights (both 1981). He quit to audition for Ozzy Osbourne’s band, whose guitarist Randy Rhoads had been killed in a plane crash. It did not work out, and Sykes was then recruited by John Sloman (formerly the vocalist with Lone Star) for his group Badlands, alongside Neil Murray on bass and the drummer John Munro. However, before the group had fully found its feet Sykes formed a new musical alliance with Phil Lynott of Thin Lizzy.

He collaborated with Lynott to record the solo single Please Don’t Leave Me, which Sykes was contractually obliged to record for MCA under his previous contract with Tygers of Pan Tang. Thin Lizzy’s Darren Wharton and Brian Downey also played on the track, and their chemistry worked well enough for Sykes to be offered a full-time job as Lizzy’s guitarist, pairing up with Scott Gorham.

Sykes featured on the band’s album Thunder and Lightning (1983), which reached No 4 on the UK chart and delivered the Top 30 single Cold Sweat, co-written by Sykes. Dates on their subsequent tour were recorded for the live album Life, and Downey and Sykes also joined Lynott for his solo tour under the name the Three Musketeers. But Thin Lizzy’s days were numbered, and the group disbanded after a final show at Nuremburg’s Monsters of Rock festival on 4 September that year. There was some discussion of Sykes joining Grand Slam, a new band formed by Lynott, but instead he accepted an offer to join Whitesnake. Lynott died in 1986, but from 1994 to 2009 Sykes played live with a reformed Thin Lizzy, performing music from their back catalogue.

In his later years Sykes became somewhat reclusive, with rumours circulating of planned album releases that did not materialise. In January 2021, he released the single Dawning of a Brand New Day, his first new song in more than two decades, with Out Alive following that April. In 2024, Appice said: “Nobody knows what he’s doing. I don’t think he’s in the business, he doesn’t like the way the business runs. He doesn’t answer emails or texts.”

Sykes married Jennifer Brooks in 1989. They divorced in 1999. He is survived by his sons, James, John Jr and Sean.

• John James Sykes, guitarist and songwriter, born 29 July 1959; death announced 20 January 2025