It comes as a shock to realise how few commercial recordings the Partridges, brother and sister, made together. Once upon a time their CfP album of Die schöne Müllerin (11/73) held its own alongside the likes of Fischer-Dieskau and Schreier ‘for its straightforward singing and plangent interpretation’, as the late Alan Blyth remarked. Drawn from a five-year period in the earlier prime of their careers, this compilation of BBC recitals shares those qualities. Both singer and pianist refined the art of simplicity. You will not find here colourful characterisations of the different personalities in ‘Alinde’, let alone the expressionist depth of despair invested by modern singers in ‘Die Liebe hat gelogen’. There is in their stead an unsentimental identification with ‘Der blinde Knabe’ and his preternatural wisdom, or the ex-lover caught unawares by an old picture in ‘Ihr Bild’. Line is paramount.

A more subtle virtue is the Partridges’ sensitivity to Schubert’s art of the unexpected. Only their slightest expansion of phrase lets us know that the spring of ‘Im Frühling’ is a time for sad memories, much as the recluse of ‘Der Einsame’ is happy alone rather than lonely. A personal discursion: the world of lieder was entirely new to me when they came to my school one evening and gave Die schöne Müllerin on a warm June evening. The memories flood back, most of all from the easy rapport, the tempo giusto and unaffected poise of ‘Nachtviolen’, where the gaze is always trained on the lovers, not distracted by the violets around them.

A sensitive reordering has produced a poetically satisfying sequence only partially compromised by song-to-song variables in level and balance between the sessions – some in mono, others in decent if airless BBC stereo – more distractingly present on headphones than speakers. Saved up as appendices are five lieder in which the tenor is accompanied by firstly himself and then Ernest Lush, ending with a perfectly judged lyric restraint in response to the pathos of Rückert’s ‘Sei mir gegrüsst’. I would hope, if this volume does as well as it deserves to, that the BBC archives could be mined more deeply; for the Partridges in English versions of The Maid of the Mill and Winter’s Journey, for English songs from Dowland to Warlock and Carter, and much more.