Bonnet and Gordon are cousins. They were born in Skegness, Lincolnshire, England, although his webpage In Memory Of states Gordon was born 18 May 1948, in Blackpool, Lancashire. While Bonnet stayed in England, Gordon grew up in Australia where he met the Bee Gees for the first time in 1964, on which Gordon recorded "House Without Windows" and "And I'll Be Happy" both songs were written by Barry Gibb In 1965, Gordon recorded another Barry Gibb compositions: "Little Miss Rhythm and Blues" and "Here I Am". Gordon returned to England in 1966 and recorded one single as 'Trev Gordon' then returned to Australia, and returned to England again in 1967 to join Graham’s band the Graham Bonnet Set. In 1968, they became the Marbles, and signed a recording contract with the Australian record label impresario, Robert Stigwood. Although Stigwood signed only Bonnet and Gordon, drummer Steve Hardy from the Blue Sect/the Graham Bonnet Set, continued to work with them. Hardy's vocal work was on the song "By the Light of the Burning Candle" (with vocals by Gordon originally, later, the song was reworked in July 1968 with Bonnet on vocals).
They were befriended by the Gibb brothers Barry, Robin and Maurice Gibb of the Bee Gees who wrote six songs for them, and provided some background vocals. "Only One Woman" was released in the UK and the US in August 1968, the single reached the Top 5 in the UK and their biggest hit. Following the release of the group's debut single, Bonnet made a remark to a reporter as to "Only One Woman" being a bit boring, angering Barry.Their second single. "The Walls Fell Down" only reached Number 28 in the same chart. But in the Netherlands it was more successful, where it reached Number 3 in their Top 40 in April 1969. Their third single "I Can't See Nobody" a 1967 Bee Gees song which was arranged by Jimmy Horowitz, the single was only released in Europe except in UK. By 1969, the Marbles had split. Their fourth and last single "Breaking Up Is Hard to Do" (third in Britain) was not charted internationally. "I Can't See Nobody" was chosen as the B-side in the UK, "Daytime" in Europe and "Little Laughing Girl" in America. In August 1970, Cotillion Records released their only self-titled album in the United States.
After the split, Bonnet started a lengthy solo career. From 1978 to 1980 he was the lead singer with Ritchie Blackmore's Rainbow. While Gordon released one solo album Alphabet and later became a music teacher, and died in 2013 in London.
The Marbles are well known to serious Bee Gees fans for covering a number of Bee Gees compositions, as well as being produced by Barry Gibb. Those expecting a sort of Bee Gees Jr., however, will be sorely disappointed by The Marbles' sole, eponymous album, even if five of the 12 tracks were penned by the Brothers Gibb. It's a far more blustery, orchestral brand of pop/rock than the relatively tender one mastered by the Bee Gees in the late '60s, even when they're doing some songs the Bee Gees themselves recorded back then (like "I Can't See Nobody" and "To Love Somebody"). Most blustery of all is Graham Bonnet's overbearing voice, which sounds a bit like a cross between Tom Jones and the Righteous Brothers, painting mental pictures of some tuxedoed guy sweating it out on the northern England cabaret circuit, his bulging neck muscles turning red with the effort. The pop and soul covers -- including "A House Is Not a Home," "Storybook Children," and "Breaking Up Is Hard to Do" -- are rendered schmaltzy by both the vocals and arrangements. The Marbles' few attempts at their own songwriting (numbering only three) are better though not great, convincingly emulating the bittersweet aspects of the early Bee Gees, though sometimes with even more ornate orchestration than the Bee Gees employed. It's of most interest to Bee Gees fans, though, for the inclusion of three Brothers Gibb compositions the Bee Gees didn't record at the time on their own records: "Only One Woman" (a number five British hit), "The Walls Fell Down," and "By the Light of a Burning Candle." They're characteristic of the Bee Gees' late-'60s style, but given such a bombastic treatment that you can't help wishing that the Bee Gees had done them instead. The 2003 CD reissue on Repertoire adds six bonus tracks, including mono single versions of four tracks from the LP and two 1969 B-sides.