This beautifully recorded new set of Beethoven’s piano trios with violinist Mark Kaplan, cellist Peter Stumpf and pianist Yael Weiss shows the composer in the process of enlarging the genre’s dimensions in order to create an equality between the three instruments. Where Mozart had written the cello part beneath the piano line in the score as if it were a continuo player, Beethoven moved it above the piano as if it were a soloist. In so doing he created the first modern piano trios.

Everything about their Archduke is memorable: the interplay of the voices, the way they smooth out the contrary movement of different lines and planes, and let the music unfold rather than just take place. Stumpf and Kaplan are superb in their solos leading into the pizzicato passage in the first movement and Weiss emerges out of their slow-motion trill as if rising from another world. The Scherzo has an unusual swinging brio and even touches of Mediterranean warmth, while the Trio has the magnificence of the Emperor Concerto, with moments of real pathos in the blurred strings. The slow variations movement is more reflective than usual, as if searching for something beyond sheer beauty. The duet between Kaplan and Stumpf in the last movement is very sweet and the Presto is really presto.

In the Ghost, their sweep to the end of the first movement shows off the rich smoothness of Kaplan’s Strad and Stumpf’s Nicolò Amati, complemented by Weiss’s clear, pure Steinway, with its wonderful depth and wealth of halftones. They phrase their dialogues with care and grace, yet they can be deft and incisive; there is a sense of movement continually being created. The iconic cello and violin solos in the last movement are played with a rocking beat as if they were distant cousins of some half-remembered Scottish or Irish tunes from Beethoven’s earlier days.

In the first movement of Op 1 No 2 Kaplan makes wonderful bowing choices that keep the music alive and interesting, and the coda is deeply touching. The trio seem to think that the first movement of Op 1 No 3 can never be too fast, as Weiss leads her mates in all sorts of merry chases, as if the composer were at the keyboard. Only Op 70 No 2 never quite finds its stride.

The trio have lots of fun in the Kakadu Variations, however, and their Op 44 Variations are special indeed. Written in 1792 on a forgettable theme from a forgotten opera by Dittersdorf, they proceed forgettably until the music explodes in the sixth variation and proceeds after a sentimental cello aria to a moment of absolute magic, with the piano singing against the pulsing strings, paced perfectly as only a few recordings have done. The remainder of the performance is unforgettable.