There are eight or so modern accounts of the Nielsen Clarinet Concerto in the catalogue, plus a few no less impressive that have come and gone. Most have fine qualities. Yet for sureness of idiomatic touch none dislodges Ib Erikson’s classic 1954 Danish accounts.

Closer to the mark than any modern rivals is this new issue from Martin Fröst, the clarinettist of the moment for all-round artistry allied to adventurous approach to repertoire. He seems to have Nielsen’s irascible masterpiece in his bloodstream, as surely as he has its technical contortions under his fingers. Vänskä ensures that the Lahti players are never fazed by the exposed edges in the accompaniment, and only the very drawn-out final bars come across as slightly self-conscious. Detail for detail, phrase for phrase, I would have to give this team the palm over the old Danish recording, even before considering BIS’s immeasurably superior sound quality. Even so, Erikson and Wöldike remain a benchmark for insight into the character of the piece.

Kalevi Aho’s Concerto starts arrestingly but without a trace of the attention-seeking that afflicts certain other clarinet concertos of recent times. There is something in Aho’s five continuous movements that recalls Nielsen’s directness and free-flowing succession of ideas, and the cadenza that forms the second movement even brings momentary echoes of Nielsen’s uncompromising skirls and flourishes. But the Finn’s sights are set more on the starkly elemental than on the quirkily personal. For Aho the Vivace con brio third movement is the “centre and culmination”, and it is certainly exuberant – dangerous, even – in its restless virtuosity, rather like Strauss’s Till Eulenspiegel driven mad by inner demons. After this a sad slow movement brings sober reflection, and an Epilogue concludes the work on a note of mystery.

Few would now question the status of the Nielsen as the finest clarinet concerto of the 20th century. Time will tell with Kalevi Aho’s concerto in the 21st. In the short term it will probably daunt as many prospective soloists and orchestras as Nielsen’s work did in its time. But there can have been few equally impressive head-on engagements with the concerto medium in recent years. In sum, a CD of rare distinction.