Robert Levin and the Academy of Ancient Music’s belated push to complete their recording of Mozart’s entire output for keyboard and orchestra continues with what might appear to be something of a mopping-up exercise. In fact it’s considerably more than that, and represents a satisfying sequence, even if none of the music here is among Mozart’s finest, and much of it is ‘borrowed’ from elsewhere.

The three concertos of K107, for example, aren’t original compositions but arrangements from spring 1772 of keyboard sonatas by Johann Christian Bach, whom the Mozarts had met in London during the previous decade. It’s not clear why Mozart made these arrangements – by this time he was more than capable of composing original concertos – but it’s abundantly clear what Mozart learnt from the London Bach, not least how to dramatise abstract music through the contrast of strident and lyrical themes and the importance of harmonic variety, the lack of which is what makes so much of the music of their contemporaries sound so flaccid in comparison.

The Concerto Movement is amplified by Levin from a draft (in Leopold Mozart’s hand) found in the notebook for Nannerl, Mozart’s sister, in which the boy’s earliest compositions were noted. It’s no stunner but it’s completed and orchestrated with style and sensitivity by Levin, and clearly the product of the same young mind as, say, the First Symphony, K16. The Concerto K175 (1773) is fully genuine Mozart and was much performed by him until he embarked upon the magnificent run of Vienna concertos in the following decade, and revised at least twice.

It’s not played on the expected fortepiano or harpsichord, either. Features of the keyboard part – its low range and lack of dynamics – led Levin to suppose that Mozart may have played it at least once on the organ, and recreates such a conjectural performance on the organ of the mellifluously named Christ’s Chapel of Alleyn’s College of God’s Gift in Dulwich.

Some action noise is charmingly audible and the chapel acoustic is noticeably more contained than that of St Jude on the Hill for the K107 concertos. The instrument in the earlier works is a copy of a Silbermann harpsichord that holds its own against the slimmed-down forces of the AAM. The programme closes with the last of Mozart’s 17 Epistle Sonatas, those single-movement works composed to cover scene changes at Sunday Mass in Salzburg. All is performed with the skill and scholarly sense of inquiry that always characterises the work of these musicians, and proves a somewhat unexpected delight.