Sorabji enthusiast David Carter has given me a link to Jonathan Powell’s world premiere performance of Sorabji’s Sequentia Cyclica Super Dies Irae Ex Missa Pro Defunctis (1948-9) – at seven hours, apparently Sorabji’s longest, and some say greatest, work. [UPDATE: Oops - Sorabji's Symphonic Variations for piano (1935-7) is nine hours long, so not true.] (After you click the play icon, don’t be put off by the brief orchestral passage that announces the show.) It is indeed magnificent and exhausting.
UPDATE: David warned me that the piece was incomplete, and indeed variations 7 and 11 are missing. But the remainder is still seven hours long. The playlist given seems to suggest that several variations are missing, but it’s only those two. Variation 22 is a 78-minute passacaglia, and the final variation, #27, is an hour-long quintuple fugue. You really going to miss variations 7 and 11?