Pop star; Born June 4, 1945; Died July 17, 2009.

Gordon Waller, who has died of a heart attack in the United States aged 64, gained worldwide fame in the 1960s as half of the harmonizing, acoustic guitar-playing duo Peter and Gordon.

Waller was born in Braemar, Aberdeenshire, the son of a well-to-do surgeon and linked up with another doctor's son, Londoner Peter Asher, for a series of hits beginning in 1964 with the Paul McCartney composition A World Without Love.

The duo toured with The Beatles, copied their hairstyles and were one of the first acts to follow the four lads from Liverpool to the US as part of what became known as "the British Invasion".

A World Without Love, written by Paul when he was 18, reached Number One on both sides of the Atlantic, the first chart-topper for a Beatles' composition not sung by the Fab Four themselves.

Waller and Asher were a bit of an oddity, a couple of toffs untypical of the pop groups of the time who were mostly working class kids from Liverpool or Manchester.

But Waller's John Lennonish-but-aristocratic look and ginger-haired Asher's horn-rimmed Buddy Holly glasses made them acceptable to parents as well as teenagers and helped bring them success "across the pond," where they were often compared to The Everley Brothers.

They met at Westminster School in London in the late 1950s.

Both played guitar, found that their voices worked well in harmony and, behind the backs of their strict schoolmasters, began making pocket money by playing in London pubs and small clubs.

After leaving school, they were playing the Pickwick Club in London in early 1964 when record producer Norman Newell happened to be in the audience and signed them up to the big EMI label.

That put them on the London music party scene, where they met The Beatles and McCartney began dating Asher's sister Jane, a budding actress who would go on to international fame in her own profession.

It was at a party in the Ashers' West End home that they heard Paul sing some verses from one of the first songs he had written but never finished.

They asked him if they could record it, Paul added a "bridge" between the verses and A World Without Love rocketed them to fame.

Two more McCartney songs (credited, as usual, to Lennon- McCartney), Nobody I Know and I Don't Want to See You Again, followed, as well as the single Woman (not to be confused with the later, different Lennon song of the same name) whose words and music were credited to an unknown called Bernard Webb - in fact McCartney.

Further hits came with cover versions of Buddy Holly's True Love Ways, Phil Spector's To Know You Is To Love You and Del Shannon's I Go To Pieces.

In his childhood Gordon Trueman Riviere Waller's two younger sisters, Diana and Anne, recall him being absorbed with his Airfix kits, any kind of puzzle and his train set. (He became a lifelong model railway enthusiast).

He and his sisters also made a bit of pocket money by setting up their own toy and sweet shop outside their dad's Braemar surgery before they were rumbled by the local policeman.

They were still children when their father moved to a practice in Middlesex and his cash and connections won young Gordon a place at the historic Westminster School, where he met Peter Asher. Throughout his schooldays, Waller loved nothing more than to take The Flying Scotsman steam train north to visit relatives in Scotland.

After the duo split up in 1968, Waller continued as a solo act with little success, his first album, Gordon, a total flop.

He set up a landscape gardening business in England before becoming a music publisher and performer first based in Glendale, California, and latterly in Ledyard, Connecticut.

In 1971, he played Pharaoh in the Lloyd-Weber/Rice musical Joseph and the Amazing Technicolor Dreamcoat on tour, including at the Edinburgh Festival.

Nearly 40 years after they split up, he and Asher, who had remained good friends, got together in 2005 for a benefit concert for their ailing friend Mike Smith, former singer with The Dave Clarke Five. Later, in 2007, they again performed together for a tribute to Elton John in New York's Carnegie Hall when they brought the house down with his I Want Love. They were scheduled to do several dates in the US and one beside the Niagara Falls in Canada starting next month.

"Gordon played such a significant role in my life that losing him is hard to comprehend - let alone tolerate," Asher said. "I am just a harmony guy. Gordon was the heart and soul of our duo."

Waller died in hospital in Norwich, Connecticut.

He is survived by his wife Jen, two daughters - Natalie and Phillippa from an earlier marriage - a granddaughter and his two sisters. By PHIL DAVISON