When Max Reger died unexpectedly at a Leipzig hotel during the night of May 10–11, 1916, he set an abrupt end to a career that was still developing at the breathless pace it had assumed by the early 1890s. In the twenty-five years that separate Reger's 1891 Violin Sonata in D minor op. 1 and his death at forty-three, the composer had produced a catalog of 146 opus numbers alongside a voluminous œuvre without opus designation, the latter including both original works and arrangements of his and other composers' music. Reger's output for the organ comprises twenty-eight opus numbers, or nearly twenty percent of his catalog, amounting to no fewer than 217 independent pieces. 1 Added to this are some fourteen original solo works without opus, at least thirty-one transcriptions of pieces for solo piano (Liszt) and harpsichord (Bach), 2 transcriptions of Reger's own works in other mediums, fourteen arrangements of Hugo Wolf's Lieder for voice and organ, 3 and several other original works that involve the organ in concerted contexts both with and without opus number. Finally, we must take into account the twenty-seven organ works of J. S. Bach transcribed for the piano between 1895 and 1901, 4 as well as the two overwhelmingly beautiful arrangements of the iconic chorale prelude O Mensch bewein' dein Sünde groß BWV 622 for violin and organ and for string orchestra, both from 1915.