Jim Diamond:​ Singer who had big hits in the 1980s with 'I Won't Let You Down' and 'I Should Have Known Better'

His rich, gritty tones earned him the 'Scotland's answer to Ray Charles' sobriquet

A songwriter with the common touch: Diamond in a 1986 publicity shot (Brian Aris)

The Glaswegian singer-songwriter Jim Diamond topped the British charts in 1984 with "I Should Have Known Better", the melancholy ballad he composed with fellow Scot Graham Lyle, of Gallagher and Lyle fame. With its memorable "I-I-I-I-I" chorus, it also became a No 1 in Australia and a best-seller across Europe.

Two years earlier, Diamond had scored another big hit with his previous project, Ph.D., the synth-pop group he had formed with the keyboard player Tony Hymas and drummer Simon Phillips, previously sidemen to the virtuoso guitarist Jeff Beck. "I Won't Let You Down" was an evocative track built around an unusual arrangement and an earworm refrain representative of Diamond's skills as a songwriter with the common touch. It reached No 3 in May 1982.

In 1986 he scored another solo smash in the UK with "Hi Ho Silver", the reggae-meets-Dire Straits theme tune to Boon, the popular ITV crime series starring Michael Elphick as the eponymous fireman-turned-private detective. All three singles remain excellent showcases of Diamond's wide vocal range, especially his spine-tingling, quavering falsetto.

Indeed, even when it was buried in 1980s production on tracks like "I Sleep Alone at Night", "Remember I Love You" and "Young Love (Carry Me Away)", it exuded a sense of longing that explained his popularity in continental Europe – where a slow dance, le slow de l'été, still goes a long way during courtship.

Diamond's success paved the way for the signing of similarly moody, melancholy-sounding UK acts to the British subsidiary of A&M Records, in particular Colin Vearncombe, aka Black, of "Wonderful Life" fame, and Sam Brown, who took the torch anthem "Stop!" into the charts across Europe in the late 80s.

Diamond's rich, gritty tones earned him the "Scotland's answer to Ray Charles" sobriquet for his occasional live appearances, a tag fortified by the R&B-infused 2005 album Souled and Healed, and City of Soul, his 2011 reinterpretations of soul classics like "Stand By Me" and "Spanish Harlem", performed with such stalwarts of the Scottish music scene as the Wet Wet Wet drummer Tommy Cunningham and Hue and Cry keyboard-player Greg Kane. What started out as a one-off concert to benefit the Radio Clyde DJ "Tiger" Tim Stevens, who had been suffering from multiple sclerosis and was forced to retire in 2010, swiftly grew into a project contributing to the Glasgow station's children charity Cash for Kids.

Born in 1951 to a seamstress and a fireman, whose dangerous work inspired the lyrics to "Hi Ho Silver", he was influenced by Ray Charles, Sam Cooke and Otis Redding, whose records his brother brought home. "That was the music I wanted to sing, because that was my love!" said Diamond, who joined his first group, The Method, in the mid-60s before moving on to the lead vocalist role in Jade alongside bassist Chris Glen, subsequently a member of the Sensational Alex Harvey Band.

This brought Diamond engagements throughout the UK and Europe, and led to a partnership with the founding father of British blues, Alexis Korner, as documented on The Lost Album, recorded in 1977 but only issued in 1995. Subsequently renamed Bandit, the highly fancied rock quintet backing Korner featured not only Diamond, but also bassist Cliff Williams, now an AC/DC mainstay; yet they broke up after just one album.

Diamond next teamed up with the David Bowie guitarist Earl Slick and the equally peripatetic drummer Carmine Appice – whose résumé includes Vanilla Fudge, Cactus, Beck, Bogert & Appice and Rod Stewart – to form the short-lived Slick Diamond. This brought the vocalist into Beck's orbit and led to the formation of Ph.D. with the guitarist's acolytes Hymas and Phillips.

Despite being the fifth act featured on the inaugural day of MTV in the US, with their 1981 debut single, "Little Suzi's on the Up", and issuing two studio albums, Ph.D. failed to follow up the success of "I Won't Let You Down" after Diamond contracted hepatitis and was unable to tour.

He moved on to a solo career: "I Should Have Known Better" was nominated for an Ivor Novello award and he became one of the ubiquitous pop faces of the mid-80s, guesting on the chart-topping charity version of "You'll Never Walk Alone", recorded for the victims of the Bradford City stadium fire and credited to the celebrity chorus The Crowd in 1985, and the No 1 revival of "Let It Be" for the collective Ferry Aid after the Zeebrugge disaster in 1987.

A man at ease with his talent and abilities, and with his fortunes bolstered by three streams of lucrative songwriting revenue, Diamond could do as he pleased. "I've never stopped making music, it's who I am," he said. "After that wonderful success I had, I took time out to raise my family and that has given me as much as music has. I'm a very lucky man."

In 1994, with Gallagher and Lyle, he recorded an engaging collection of traditional Scots ballads, Sugarolly Days. He also tried his hand at radio presenting and playwriting. His generous outlook enriched the friendships he developed with Cunningham, Kane and the Scottish billionaire philanthropist Sir Tom Hunter, another prime mover behind Cash for Kids.

"I worked with Jim in 2011 on the City of Soul album," Kane recalled. "We produced the record together. We shared many a night after the days' sessions talking about our experiences in the music business. He told me some of the most fascinating stories, ranging from Father Ted to AC/DC and everything in between. I've dined out on many of them many times since. He was a great storyteller, that came across in his music. As with most creative people, Jim could be stubborn, but he was usually right. I'll miss him."

James Aaron Diamond, singer, songwriter and producer: born Glasgow 28 September 1951; married 1978 Christine Bailey (one daughter, one son); died London 8 October 2015.