It was the appearance of John Ogdon’s remarkable LP set of the Passacaglia on D.S.C.H. in 1967 that alerted collectors to Ronald Stevenson’s music. He composed the Passacaglia between 1960 and 1962 and, like Sorabji’s Opus clavicembalisiticum or Busoni’s Fantasia contrappuntistica (Stevenson is a keen and persuasive advocate of that composer), it is something of a tour de force. It is a mighty set of variations on the four-note motif D-S-C-H derived from Shostakovich’s monogram, lasting without a break for some 80 minutes. Later on in the score Stevenson introduces another four-note anagram, B-A-C-H, perhaps a reference to Busoni’s Fantasia contrappuntistica. When he presented Shostakovich with the score at the 1962 Edinburgh Festival, he said that the combination of Russian and German motifs symbolised his hope that the two nations, and mankind generally, would live in harmony. The twelfth section cleverly alludes to the microtonal scale of the Highland bagpipes and incorporates a seventeenth-century Pibroch Cumha ne Cloinne (“Lament for the Children”) and there is a formidable climactic triple fugue in which the Dies Irae surfaces. In the 1960s Sir William Walton hailed the pieces as “really tremendous – magnificent- I can’t remember having been so excited by a new work for a very long time”. Murray McLachlan is an impressive exponent of this score and he is very well recorded. Some years ago he recorded the two piano concertos that Stevenson wrote at about this time, so he is completely attuned to this music.