‘Who was Johann Gottfried Müthel?’ asks the booklet-note, with good reason. For some his name might strike a faint bell as one of JS Bach’s last pupils. He later met CPE Bach in Berlin, and corresponded regularly with him after he became Kapellmeister in Riga. Müthel’s many admirers included the English music historian Charles Burney, who in 1773 wrote that his compositions ‘are so full of novelty, taste, grace and contrivance, that I should not hesitate to rank them among the greatest productions of the age’. While my own rapture was slightly more modified, his five harpsichord concertos (he composed almost exculsively for the keyboard) reveal yet another 18th-century composer who deserves to be rescued from posthumous oblivion.

Born in 1728, Müthel was of the generation of Haydn and Johann Christian Bach. One or two movements, above all the pastoral, siciliano-style Adagio of No 2 in D minor, charmingly coloured by a pair of bassoons, might be mistaken for Johann Christian. More often, though, Müthel seems to take his friend CPE as his model: say, in the musingly ornamental, empfindsam Adagios, the cussedly angular first movement of No 1 and the high-voltage finales of Nos 2 and 6. More than CPE, Müthel highlights virtuoso brilliance, throwing in dizzying swirls of semiquavers and demisemiquavers, mini-fantasias and cadenzas – testimony to his own keyboard prowess.

No one could claim Müthel as a great tunesmith. With rare exceptions, gesture rather than singing melody is the order of the day. Some of his quasi-improvisatory writing, especially in first movements, can be meandering and repetitive – something you rarely find in CPE. Yet this is ear-tickling music, sometimes rather more than that. In her informative note, Regina Rapp suggests that Müthel’s concertos ‘live or die by the subtlety with which they are performed’. Well, they certainly live here. Playing on a fine, sonorous copy of a 17th-century Ruckers harpsichord, Marcin Świątkiewicz relishes both the flamboyant virtuosity of the fast movements and the delicate sentiment of the Adagios – not so delicate, either, in the florid, Baroque-inspired rhetoric of No 4. He makes colourful use of the instrument’s contrasting manuals and has a subtle sense of rubato, aware that time borrowed should also be repaid. Świątkiewicz's eloquent advocacy is matched by the 10-strong strings of Arte dei Suonatori, spruce and rhythmically buoyant, mitigating the ‘chug’ factor in Müthel’s repeated-bass accompaniments. The recorded sound is ideally warm and lively. Recommended to anyone who enjoys CPE Bach’s concertos and wants to venture into one of the century’s agreeable forgotten byways.