A primary source for Beethoven scholarship revealing the creative processes of one of the greatest masters of musical art, this three-volume set makes available in print for the first time "Artaria 195", the large-format sketchbook and central document for Beethoven's compositional activity during 1820. "Artaria 195" includes sketches for two of Beethoven's masterpieces: the Piano Sonata in E Major, Op. 109, and the Missa solemnis, Op. 123. It also preserves Beethoven's work on the Bagatelles Op. 119, Nos. 7-11, and other unknown brief piano pieces. Beethoven's sketchbooks were his workshop. Capturing the methods he used to craft his ideas into art, they reveal his complex creativity and offer rich material for examining his revision process. Variations in his entries reflect the range of his musical moods and offer clues about the circumstances of composition. His notes and shorthand can illuminate the ways he expanded and refined ideas, clarify biographical or musical mysteries, or call attention to deliberate links between compositions. This edition includes a full-scale colour facsimile edition of this major sketchbook. New light is shed on the genesis of his last three piano sonatas, and revealing perspectives emerge on the psychology of his creative process.