With the Edinburgh International Festival’s survey of Beethoven’s Piano Sonatas well passed now, the Beethoven baton passes to Glasgow for the final instalment of the city’s three-year focus on the composer’s String Quartets and Piano Sonatas in the company of pianist Llyr Williams and the Elias String Quartet. In this final episode, a series of concerts, which began last night will run through the weekend. There is one element within it that is of particular interest to this column, and that is an event tomorrow afternoon entitled "Getting To The Heart Of The Grosse Fuge, op133”. It’s at 2pm in the City Hall, and the Elias Quartet will deconstruct and explore this most intimidating of pieces, before playing it complete.

There’s a colossal story in connection with this piece, which would take weeks to tell. Let’s see today what we can get through. In 1826, the year before Beethoven’s death, the Great Fugue was premiered in Vienna. At that point the Fugue was the finale of the B flat String Quartet, opus 130. Beethoven didn’t go to the concert: by that time there was nothing the deaf composer could have heard. He went to the pub instead, and awaited a report from trusted friends. He was informed about which movements had been encored. “Not the Fugue?” he retorted, describing the audience as “cattle” (not the word he used, I would suspect).

He was told that this fugal finale was the most unapproachable, impenetrable thing he had written, and was begged to remove it and offer a replacement finale. Astonishingly, instead of thumping his commentators, Beethoven acquiesced, writing an alternative final sixth movement, a stonking, jaunty masterpiece in its own right. He also removed the original fugal finale, gave it a separate work number, opus 133, The Great Fugue, and set it off on a life of its own. It’s still occasionally played that way (the SCO strings have done it) though it’s now pretty much reintegrated as the original finale to the opus 130 quartet.

Soon after the premiere of the Great Fugue, Beethoven’s publisher wanted to print, for sale, a transcription of it written for piano duet: for four hands at one piano. The publisher didn’t ask Beethoven to do it. Why, I don’t know. Instead, the publisher commissioned a minor musical figure to do the transcription. Fine; until Beethoven saw it. I will leave to your imagination what he probably said. But he decided to do it himself, and gave it the next work-number up the ladder: opus 134.

The voluminous manuscript on which Beethoven wrote this duet version disappeared after his death in 1827. Missing, presumed lost; and it stayed that way through world wars, revolutions of every hue in the 19th and 20th centuries, through God knows what political, geographical and physical turmoil, and into the present century. Until July, 2005.

If you know the story of what happened next, you might be nodding in recognition. If you don’t, you might be incredulous. That summer, in Philadelphia of all places, a librarian, Heather Scarbo, working in the Palmer Theological Seminary, was clearing out an old archival cabinet. She came across a great wodge of music manuscript in a safe. She asked the right questions of the right people and forensic examination of the music took place. It was the original manuscript of Beethoven’s opus 134, 80 pages of it, in the composer’s own hand, complete with all his scratchings and rubbings-out and, moreover, his own-devised fingerings to help make approachable the music that had been unthinkable and unplayable. It is the only complete manuscript score of the piano version. Having been fully authenticated, the manuscript went on auction at Sotheby’s in 2006. It was bought for more than £1m by a publicity-shy billionaire and donated to the Juilliard School of Music, where it now resides.

I’ve looked at it online. That was a very weird experience. I sat transfixed, staring at Beethoven’s handwriting, up close. It looks as though he was writing at high speed. You can almost sense the composer’s bluntness and directness. I’ve no idea how long I sat there, not speaking, not even thinking, just aware of this enormous presence.

The last-known mention of the manuscript was at an auction in 1890 in Berlin. No buyer is named. It’s believed it might have been a Cincinnati businessman, William Howard Doane. In 1952 Doane’s daughter made a gift to the Eastern Baptist Theological Seminary, to establish a chapel. The gift included music manuscripts, with certainly manuscripts by Mozart. It’s possible that Beethoven’s opus 134 manuscript was among them. Many folk, including Stravinsky in the last century, have spoken with awe of the Great Fugue. It’s still as awesome; but perhaps a little closer now.