Joyful anticipation at 80 minutes of previously unreleased live performances from Aldeburgh, given by two Russian giants and their composer-pianist mutual friend, is temporarily dampened by the recorded sound, which is distractingly hissy and acoustically less than grateful, especially for the piano. But the discomfort passes, thanks to passionate communication, matched by formidable intellectual control and sparking off against it. Richter offers no apologies for the chunkiness of Brahms’s piano-writing, but the amplitude and range of Rostropovich’s tone show that no such apologies are needed. Neither player is embarrassed by the obviousness of Grieg’s melodrama; instead they do everything they can to maximise it, and both they and the music emerge triumphant.

With Britten as accompanist, the first movement of the Shostakovich is if anything even more driven than in Rostropovich’s account with the composer, but any hint of loss of character is soon forgotten as the large-scale vision and sheer presence of the playing work their magic. Admittedly a few spills accompany the thrills – the tricky conclusion to the Scherzo for one, and the piano’s last note for another – but that is merely a concomitant of music-making that has its sights set far beyond perfection. All three performances are documents to treasure, and Tully Potter’s sympathetic accompanying essay is another bonus.