A music sequence that is especially close to the hearts of these prodigiously gifted siblings, the Barber Sonata penned by a comparatively young man, the Rachmaninov following along the lines of the roughly contemporaneous Second Piano Concerto, and like the concerto an unstoppable fund of melody. To fill available disc space the Kanneh-Masons have programmed a number of song transcriptions arranged by Simon Parkin (Barber) and Sheku himself (Rachmaninov). If you fancy a short, expressive sampling of what these players are capable of, try track 4, the intimate, folk-like song ‘There’s nae lark’, and some of the loveliest cello-playing I’ve heard in decades, considerately accompanied by Isata. Of the Rachmaninov songs, perhaps ‘How fair this spot’ is the most enchanting, especially at 1'02" when Sheku glides into the instrument’s tenor range on the edge of a hypnotic pianissimo.

The two sonatas require of their interpreters both passion and a sense of scale, not to mention an ability to think through – and cope with – some extremely demanding technical issues. In the Barber, maybe Kathryn Stott (with cellist Christian Poltéra, with the Concerto and Adagio for Strings as couplings) sustains the finale’s thunderous opening with marginally more emphasis on his dramatic employment of the instrument’s lower extremity but in the Adagio, beyond the central tarantella-like Presto (where Isata is especially brilliant), Sheku’s playing reaches the sort of lofty emotional peak you’d have expected from a du Pré or a Navarra.

In the Rachmaninov Sonata, perhaps the nearest viable point of comparison among more recent recordings is Alisa Weilerstein with pianist Inon Barnatan (coupled with a Chopin selection, including the Cello Sonata). Here the issue isn’t so much preferences as contrasts: in the finale’s second subject, for example, where Weilerstein cuts the smoother profile and Kanneh-Mason commands a marginally more varied roster of colours while Barnatan scores in terms of tonal subtlety. At the start of the Scherzo, the newer version has a more impatient, stealthy feel to it.

But it’s a close-run contest: both partnerships deliver handsomely (especially in the Andante’s gorgeous coda) and both recordings are excellent in their different ways. In the Barber, Decca achieves the greater immediacy, whereas BIS creates the sort of ambient sound world you’re likely to encounter in recital. In the Rachmaninov, the Kanneh-Masons are sonically closer to hand than Weilerstein and Barnatan, who are nonetheless focused with impressive brightness and clarity. All three discs can carry a confident recommendation but this latest release is the most enterprising, musically.