Ah, if only that clip had begun slightly earlier, Pim - we would have the answer to our mystery
Meanwhile, forthcoming Christmas books on the topic include:
Dan Brown: "The Figured-Bass Code" - numeration found below the bass-lines of Bach's Brandenburg Concertos, previously thought to be a shorthand version of the harpsichord part, is in fact an encoded cipher of the GPS location of the Holy Grail.
David Icke: "JS Bach, the Reptilian Shape-Shifter" - how Bach was forced to hide the slow movement of his Brandenburg Concerto No 3 because it revealed his membership of the Illuminati, The Freemasons, The Order of The Cross Of Malta, the St Johns Ambulance Brigade, etc. Including pictures of Bach at Bohemian Grove with Froberger and Muffat, and why the Slow Movement is kept from the public to this day by other reptilian shape-shifters including Radio Three, and (cont p94).
Alex Jones: "The Truth About 6/3" - the companion volume to "The Truth About 9/11"
Paul McKenna: "I Can Make You Improvise The Slow Movement Of Brandenburg 3" - suitable for all instruments (a separate edition for saxophones, trumpets, euphoniums and other instruments in Bb is available). Incudes a cd of both chords played by the world-famous Vladivostok Philharmonic Baroque Symphony Orchestra Ensemble in sonorous mono.
Norman Lebrecht: "Why Bach Is Rubbish" - Bach was such a rubbish composer that he couldn't think of anything for the Slow Movement. Britain's leading musicoffeetablogist examines the elaborate hoax that suggested Bach was a great composer, along with suggesting that all music written after 1883 was also rubbish, that classical music is dead, etc. $10 from every copy sold goes to the Fighting Fund against the Naxos judgement. Now available from £1 shops and remaindered-booksellers all over Acton.