According to Clayson, his first band was Ace and the Crescents, which he formed in the mid 1960s with fellow students from "a truly desperate grammar school for boys near Aldershot [in Hampshire]". He recalls visiting the Beatles' Apple Corps headquarters in 1968, in an unsuccessful attempt to have Apple publish his poetry. With beat music, psychedelia, chanson, mediaeval and modern classical among inspirations, he formed Clayson and the Argonauts in the late 1970s. The band received some highly favourable reviews in the UK music press, attaining what Melody Maker termed "a premier position on rock's Lunatic Fringe", yet only achieved minor commercial success in Northern Europe.
Following the disbandment of the Argonauts in 1986, Clayson continued as a recording artist and solo performer. The Village Voice described his act as "more than just a performance; an experience". Since 2011, he has also fronted a stage presentation entitled Clayson Sings Chanson. Clayson's songs have been covered by Dave Berry (in whose backing group Clayson played keyboards in the mid-1980s), Stairway and Jane Relf. He has also worked with the Portsmouth Sinfonia, Wreckless Eric, Jim McCarty, Dick Taylor and Screaming Lord Sutch, among others. Clayson and the Argonauts re-formed in 2005.
As journalist and author
Having contributed to Schoolkids OZ during his adolescence, Clayson went on to write regularly for a wide range of publications, including Record Collector, Mojo, The Guardian, The Independent, Folk Roots and Mediaeval World. His work has also appeared in Hello!, The Sunday Times, The Daily Telegraph and Ugly Things.
In his role as a pop music historian, Clayson has written over thirty books. The English newspaper Western Morning News once labelled him "the AJP Taylor of pop", with reference to the esteemed historian of twentieth-century European politics. Clayson's bestsellers include Backbeat (subsequently made into a film by director Iain Softley); Beat Merchants; and an authorised biography of the Yardbirds.
In addition to Backbeat, he has written books on each of the four Beatles, beginning with the 1990 publication of The Quiet One: A Life of George Harrison. The four titles were re-released as a box set in 2003 by Sanctuary Publishing. Clayson's volume on Ringo Starr, subtitled Straight Man or Joker?, remains a rare work dedicated to the drummer's career. In his overview of the most popular Beatles books, for Rough Guides, Chris Ingham writes that the four volumes "have been described as Beatles-flavoured teabags in a cup full of Clayson", due to the author's tendency to refer to his own musical career and insert his "harmless prejudices" in the narrative. Ingham concedes, however, that "as a second-generation veteran of the British beat scene, [Clayson's] point of view usually contains a certain authenticity and authority."
Clayson has also written English-language studies of the French singer and actor Serge Gainsbourg, French composer Edgard Varèse and Belgian chansonnier Jacques Brel. His other subjects include Led Zeppelin, Mick Jagger, Brian Jones, Charlie Watts, Keith Richards, Keith Moon, Roy Orbison, Yoko Ono and the Troggs.
Aside from his writing on popular music, Clayson has presented radio programs and lectured on music in Britain and the United States. He has also contributed liner notes and commentary to CD and DVD releases by artists such as Elvis Presley, the Rolling Stones, Édith Piaf, Peter Frampton, Matt Munro, Buddy Holly, Jimi Hendrix, Steve Harley, the Animals and Mungo Jerry.