This series is written from published material and its byline claims method rather than credentials, so the sources are listed. They are given as books and categories of material rather than as page citations; where a claim in the text is contested, the text says so at the point of the claim.
Histories of the genre. Rocking the Classics: English Progressive Rock and the Counterculture, Edward Macan, the fullest scholarly account of the music’s classical borrowings, its class base and its audience, and the source this book leans on for the formation story of Movement One. The Show That Never Ends: The Rise and Fall of Prog Rock, David Weigel, the best narrative history, strong on the American careers and the touring economics. Listening to the Future, Bill Martin, argues the genre’s case philosophically and is used here as a document of the defence.
The machine. Mellotron: The Machines and the Musicians that Revolutionised Rock, Nick Awde, interviews with the Bradleys’ circle and the players; the Chamberlin–Fransen story and the tape-library accounts in Movement Two follow the tellings collected there and in the specialist literature of the instrument’s collectors, with the contested details flagged in the text. Trade and musicians’ press of the period (Melody Maker's equipment pages, International Musician, Studio Sound) for instrument prices, studio rates and the track-format chronology.
Memoirs and participant accounts, all read as interested tellings: Nick Mason, Inside Out: A Personal History of Pink Floyd, the Norton Warburg affair and the tax-exile year follow his account and the contemporaneous press; Bill Bruford, The Autobiography; Greg Lake, Lucky Man; Keith Emerson, Pictures of an Exhibitionist; Ian Anderson’s extensive interview record on the Thick as a Brick sleeve and the 1973 retirement announcement; Rick Wakeman’s several volumes of anecdote, which the text treats explicitly as performances with variable garnish; Robert Fripp’s published diaries, which document the EG dispute from one side, as the text says.
Band histories. Genesis: Chapter and Verse, the band’s authorised oral history (the Lamb tour finances and the Charterhouse prehistory; Close to the Edge: The Story of Yes, Chris Welch; In the Court of King Crimson, Sid Smith) the 1969 formation and Hyde Park accounts.
The money. Mechanical-royalty structures, recoupment practice and the packaging-deduction conventions are standard industry practice of the period, set out in any reputable music-business text; Donald Passman’s All You Need to Know About the Music Business remains the clearest general explanation, though it describes a later era, and the specific percentages in Movement Four are illustrative, as the text says at the point of use. British tax rates are from the Finance Acts of the period. The Fisher v Brooker organ-line ruling is public record: the House of Lords judgment of 2009. The Norton Warburg collapse was reported in the British financial and music press of 1981 onward.
Charts and dates. The Official Charts Company (UK), Billboard (US), and the Italian industry’s historical charts for the claims about Italy, which the text hedges where the compilations of the period were informal.
Where figures are disputed (the Hyde Park crowd, the Mellotron settlement, the Works tour losses, the Lamb tour deficit, the Norton Warburg total, the size of the era’s biggest recording budgets) the text names the teller and gives the range rather than choosing a number. Those disagreements are not gaps in the record. They are the record.