Paul von Klenau (1883-1946) was a Danish composer who went from writing like Bruckner to writing like Schoenberg, living much of his life in German-speaking countries. All three works recorded here were included in a bundle of manuscripts handed to the Royal Danish Library in 2005 and all date from the war years, shortly before the composer died. None had been heard before two Klenau concerts given by Hans Graf and his Singapore Symphony Orchestra in 2021 and 2022, after which these recordings were made.

Klenau is notable for using 12-note methods in both atonal and tonal styles. The first two works here fall into the latter category. In the Violin Concerto, tone rows stand out from the tonal context – not incongruously, though they can lead to a certain wandering and a general lack of focal emphasis that the music’s neoclassical footing seems to want. The soloist is rarely not busy in the 15-minute opening movement (as long as Klenau’s Symphony No 8) and Ziyu He plays with finesse and emotional investment, immaculate in the figuration and double-stopping and with an appealing tone. The slow movement is the concerto’s gem, the soloist spinning a 12-note web with the orchestra as its shadow underneath. Here, the sense of inertia that can dog Klenau’s music elsewhere only aids its effect.

In the Piano Concerto, as in its violin counterpart, tenderness blossoms momentarily like flowers between rocks. There is more of Klenau’s spartan directness here, though the main theme that emerges in the first movement is James Bond-esque in its modal ambiguity and is fleetingly luxuriated in by the fine Singapore strings. The composer tends to stride abruptly through harmonies almost like Jón Leifs, and a sort of vigorous, binary conversational counterpoint rooted in rapid exchange emerges as one of his hallmarks (the music’s simplicity can both endear and frustrate). The pent-up anxieties of war and illness make themselves felt but so does a sense that the language isn’t joined up – that Klenau’s own ‘key-determined 12-note system’ isn’t delivering the fluency outright serialism did for, say, Fartein Valen.

Still, just as you’re totting up criticisms of Klenau, his music turns to surprise you. The Piano Concerto’s slow movement has a distinctive smiling unease, before freewheeling from some proto-minimalism (passages could be Philip Glass) into a more complex and elusive beauty. Søren Rastogi does much with a score that, elsewhere, can be hard to caress.

The composer’s Symphony No 8 is the most forgettable piece here – indeed, Klenau himself forgot it, numbering his Ninth his Eighth by accident. It’s a homage to Mozart that can sound like a very mid-century take on classicism, with heavy dancing feet and too much hammering timpani. Perhaps the concertos are more likely to grow on you. They get fine performances here in good sound from the Esplanade Concert Hall.