Groh (1905-82) and Kullman (1903-83) were almost exact contemporaries, and were of that school of German tenors who sound “a bit like Richard Tauber”. Kullman was born of German parents in the United States and is often listed among American singers; but the voice had essential affinities with the Austro-German school and, within that school, he was quite closely akin to Groh. Both singers cultivated as primary assets beauty of tone (rather than power), an even vocal line (rather than emphatic treatment of words), broad phrasing and ease in movement within the voice’s range and volume. Kullman’s was the fuller, warmer voice and his was the more distinguished career, taking him to several of the world’s leading houses. But Groh gives comparable pleasure on records and indeed was a singer of great accomplishment. When their records are played side by side, their separate identities are quite clear, and if Tauber is added for further comparison he is seen to be different again, being the most individual and distinctive of all.

Of Groh’s recordings, the farewell from Mignon is as good an example as any, voice and music perfectly suited. The romance from Les pêcheurs de perles is another lovely example, as is the rare Semiramide aria, so mellifluous and Italianate in performance. Duets with Emmy Bettendorf and Gerhard Hüsch are also models of graceful, well schooled singing, and though the solos from Die Meistersinger, Aida and Pagliacci are not his by nature, he makes a well mannered show of compatibility.

Kullman has much more naturally the measure of his “Holde Aida” and “Morgenlich leuchtend”. There is power in his voice but also a velvety softness, which he uses to a seductively romantic effect in Vladimir’s cavatina from Prince Igor and in the many items from operetta included here. It’s notable too that while both sing the Italian tenor’s aria from Der Rosenkavalier with delightful evenness and thrilling high notes, Groh’s pronunciation and phrasing are provincial compared with Kullman, who gets them right.

But I fancy it is another consideration which will make Kullman’s disc the more satisfactory proposition for most likely buyers. That is the superiority of sound in terms of original recording and transfer. Nimbus’s new method does Groh no favours: as 78s his records can play beautifully but here the process brings out from time to time an edgy hardness.

Personally, I valued the “old” Nimbus method partly because it was on its own and offered an alternative, and partly because most modern equipment bought in the shops is so hard and unkind to voices and old recordings that the Prima Voce series was about the one thing it couldn’t distort. Now that is gone, and the new method sounds, in kind, like all the rest.