If you already have Christophe Rousset’s fine two-disc set of harpsichord pieces by Louis Couperin on Aparté, there’s no need to feel miffed that here, only nine years later, is another. Far from signalling dissatisfaction with his earlier efforts, it is almost all of different pieces, and together the two sets offer about 100 of Couperin’s total of about 130 short pieces. Not that Harmonia Mundi tells us that, either on the outside of the box or anywhere in the booklet. It took me a while to work it out myself.

That fact also explains the absence of more famous pieces such as the C major Passacaille or the Tombeau de M Blancrocher, as well as the strange disposition of some of the suites. In the manuscripts in which Couperin’s music survives, the various preludes and dances are rarely gathered into suites, leaving that job to the performer. On the Aparté discs the suites – Rousset’s first choices, one imagines – are neatly and compactly organised around a basic sequence of prelude, allemande, courante, sarabande, gigue and passacaille; on the Harmonia Mundi set the suites sprawl, often containing two or three of the same type of movement; one even ends with a spare prelude. Fortunately, Couperin’s music is of consistent quality, and there are still plenty of gems to be enjoyed here from a composer who was one of the true creators of French harpsichord music but whose exquisitely crafted music still speaks to us today with nobility of soul.

There is another very good reason why this release is justified, namely the harpsichord, a stunning 1652 instrument by the Antwerp maker Ioannes Couchet, enlarged in 1701 by unknown French hands and today living in the Philharmonie de Paris’s Musée de la Musique. The result is a classic combination of Flemish sweet-singing delicacy and French deep tone – many of the pieces bask in a gentle halo of resonance and the final chord of one prelude (track 7) rings on for 15 seconds. Rousset is just the sort kind of player to take advantage with his precise yet silken touch and immense authority in the French harpsichord style, which sees contrapuntal lines delineated with clarity, ornaments inlaid with relaxed grace and spread-chords delivered with flowing expressiveness. He is also a master of the unmeasured prelude, bringing intellect and improvisatory freedom together with firm assurance.

Louis Couperin has been taken up in recent years by pianists such as Pavel Kolesnikov and Pierre Chalmeau, with sometimes interesting results, but it is wonderful here to hear it sounding such a soul-partner for the harpsichord.