The piano duo is hardly a new, novel or modern idea. The finest early example, from 1779, is Mozart’s Piano Concerto No. 10 in Eb K365 for Two Pianos. He did write Concerto No. 7 in F major K242 for Three Pianos in 1776, but let’s not go there. In jazz, two pianos in duet is a rabbit hole into which few have chosen to descend, the most notable being Duke Ellington and Billy Strayhorn, Ran Blake and Jackie Byard, and at various times, Herbie Hancock with Chick Corea, Joe Zawinul and Fredrich Gulda.

It’s a pretty exclusive club because of the challenges it poses, never mind the mathematical permutations available to 20 digits confronted with 176 possible note choices;it suggests the stars need to be in perfect conjunction for inspiration to flow.

Kühn and Wollny, who number among Europe's finest pianists, are no strangers to releasing the inspiration valve but on Duo, their second such recording together, the celestial spheres seemed to drift in and out of alignment. On ‘Vienna Pitch’ the exchanges are tentative and pretty basic, but on ‘Somewhere,’ ‘My Brother Rolf’ and to a degree on ‘Activ,’ flashes of inspiration occur, presenting moments when two become one in thought and deed that briefly gave meaning to the album.