Missing autographs raise problems. Three of these concertos survive only through manuscript copies printed or handwritten, No 4 the lucky exception. Unsatisfactory; but Keith Warsop explains the circumstances in ‘The Publication History of Spohr’s Clarinet Concertos’, his recent article for the composer’s society. Arresting music, though, and tough on soloists because Spohr scorned restrictions. ‘He wrote first and asked afterwards,’ says Pamela Weston, but he would not have had to ask Maria du Toit, well in control of the notes if not always their guiding spirit.

Secure too is Arjan Tien, most sympathetic to her when she chimes with the introversion within the music, jointly in tune with the melancholia uppermost in the E minor tonality of No 4. Literal minds may object to the first movement’s tempo, nine points lower than Spohr’s specified crotchet=132; and also object to perhaps an exaggerated poco meno mosso at 6'09". But there is no gainsaying the grave beauty deeply felt in this movement, in the Larghetto and even in the long E major section of the finale.

Not as unswerving are the other performances, largely because du Toit isn’t comfortable with bravura. She holds back; and passionate advocacy for, say, the coruscating outer movements of No 2 is only partially forthcoming. Tien ought to have empowered her to break free but misses out on fulfilling so crucial a part of his role. Instead he’s dutiful or rhythmically heavy, as in the first movement of No 3, and the orchestra dutifully follows him. Robin O’Neill better supports Michael Collins in fine fettle – and in a fine Hyperion recording. But neither conductor matches Paul Meyer who, as his own conductor, creates cohesive yet mercurial frameworks for eruptive interpretations and is equally at home with the angelic or the demoniac. Alpha’s contrived orchestral sound, however, irritates with repetition. Brilliant Classics’ production, flawed by changes in levels between movements, is nonetheless airier and clearer, instruments in better balance. Unflawed though is the angelic as expressed by du Toit in the other slow movements, evocatively phrased, tenderly yielding, the chalumeau register exquisitely ethereal. Introversion – again.