That Le Roux was a teacher is beyond doubt, since a pedagogical intent is prevalent in not only the volume’s contents, but also in the advice he proffers in its preface. As far as printed collections are concerned, this is quite unique: he suggests singing the melody with basso continuo accompaniment before playing it, something for which the music’s layout is eminently suitable. It was common for teachers to prepare music for their students to copy and we can assume that Le Roux’s practices were similar since his preface states:
Quoy que Je n’aye épargné ny mes soins ny mes peines, pour mettre mes compositions de musique au meilleur estat ou elles pouvoient sortir de mes mains, Je n’ay Jamais eu en veuë de les exposer aux yeux du Public. Mais encouragé par des Gens qui ont beaucoup de connaissances, et touché des fautes grossieres que j’ai remarquées dans les copies qui ont couru malgré moy de mes pieces de Clavessin, J’ay enfin pris la resolution de les faire graver, et de pressentir le goust du Public, qui seul peut decider du merite des ouvrages.
Although Le Roux was not the first composer to use this excuse as justification for going to print, his preface nevertheless suggests that at least some of the pièces were composed considerably earlier than their publication date, but when this occurred is unclear. Some aspects of the G minor Sarabande appear to show the influence of Corelli’s La Follia, indicating that it might have been written after 1700, but little information of a similar nature may be gained from examining the style or content of the remaining dances. The notation of the préludes non mesurés is somewhat archaic, suggesting the influence of an earlier generation of composers such as Louis Couperin, but this by no means indicates when they were written, since their semibreve notation is wholly appropriate for such simple pieces, with figuration easily identifiable and structures highlighted by the occasional use of figured bass. None includes similar rhythmic devices to those found in, for example, D’Anglebert’s printed preludes, which makes their interpretation considerably easier. From this perspective, the suggestion of a pedagogical intention is reinforced, as it is from the undulating appearance of the tenues, which allows easier differentiation between harmonic and melodic material. They appear to copy Clérambault who is the only other known composer to universally apply similar lines, which makes it possible to put at least the compilation of Le Roux’s pièces into an approximate timeframe: if the Clérambault connection is correct, it is likely that Le Roux put his music ‘au meilleur estat’ sometime after 1702, when the first edition of Clérambault’s Pièces de Claveçin was published.
As with most demonstrational collections, Le Roux provided several types of treatment for different genres and playing approaches: the Allemande la Vauvert is a standard French common-time allemande, with unequal semiquavers; la Lorenzany and l’Incomparable, in two-time, are more march like, with unequal quavers; Allemande Grave (V) is a touch slower because of its intricate chutes; and Allemande gaye has the character of an ouverture in its first section with short demisemiquaver tiratas and plain crotchet chords in the reprise, suggesting a fairly quick and even approach, the ‘gaye’ of the title possibly meaning the equivalent of François Couperin’s ‘sans lenteur’.
Like Louis Couperin, Le Roux includes many devices derived from lute style, in particular in the allemandes and courantes, where brisure is often used to maintain quaver movement and provide the dance’s melodic features. The textures are sometimes fuller than Couperin’s, however, and the more active basses alongside clearly developed imitative and sequential devices demonstrate that Le Roux was quite familiar with D’Anglebert’s practices.
From a harmonic viewpoint, there is little that is retrospective about the music. Le Roux’s use of bold, unexpected and sometimes brash progressions often appears more progressive than some of his contemporaries, as does the use of descriptive or dedicatory titles: in addition to the allemandes la Vauvert, la Lorenzany and l’Incomparable, the Courante la Venitiene and the loure La favoritte, two freely-composed movements are named la Bel-ebat (a diversion or entertainment) and, ironically, la Piece sans titre. These are amongst the first examples of published character pieces in France, a genre that would become increasingly fashionable in following years with composers such as François Couperin and Jean-Philippe Rameau.
There is nothing unusual about the interchangeability of instruments during the baroque period and common sense informs us that ensemble music must have been performed on whatever instruments were to hand. Printed examples, some dating from as early as the 1660s, suggest that the purism afforded today’s musicians was not a burning issue. Le Roux sustains this thesis by not designating instrumentation for the trios, ensuring instead that the music does not, for the most part, exceed the lower ranges of any common instrument. Where it does, Le Roux is careful to indicate that a line might be played at a different octave through the use of guidons to show where to change. In effect, this makes the music transmutable to the extent that we are also provided with the additional options of performing the pieces as harpsichord duets, or as instrumental solos with an accompaniment derived from the trios’ contreparties and basso continuo lines.
The notion of a contrepartie was nothing new, since the addition of a supplementary countermelody found its main outlet in lute repertoire during the 17th century. For example, Denis Gaultier’s courantes La belle and Le canon homicide were provided respectively with two and three different contreparties and a Swedish manuscript part-book that now resides in Berlin (unfortunately without the first lute part) contains no less than 93 contreparties to lute pieces by various composers. Although it may appear that the practice was limited to lute alone, the large number of extant secondary lute parts is probably because tablature is not a convenient medium from which to extemporise. Keyboard music, however, was and in addition to providing new options for performance, as a teaching tool the practical value of an accompaniment would have been immense. This must have been something of which Le Roux was aware, since he addresses the issue of improvisation not only by emphasising the ensemble aspects of the collection, but also by describing the manner by which the pieces may be played as duets:
La plus part de ces pieces font leur effet à deux Clavessins, l’un joüant les sujet, l’autre la contrepartie. On en verra l’exemple par les six pieces qui sont a la fin du Livre.
From this perspective Le Roux’s qualities as an intuitive pedagogue again become apparent since, like the allemandes, the contrepartie realisations that complete the Pieces de Clavessin are demonstrational, covering most of the common genres. Although their order appears haphazard, they allow for the implementation of different skills in realising secondary harpsichord parts. This is spearheaded by the gigue, which is provided not only in full score with both harpsichord parts, but also includes a trio arrangement. In itself, this is quite unique. It is the earliest known French keyboard duet to be printed, and combined with its accompanying trio, provides an object lesson in the possibilities of scoring. Since the piece cannot be played effectively as a solo, it must be that it was written purposely for this part of the volume. It nevertheless acts as a summation of the guidelines provided by Le Roux in the ensuing movements.
These begin with the contrepartie of the G minor Courante, which also contains with the trio’s continuo line in a demonstration of how the bass might be elaborated through the discreet application of brisure, inclusion of passing notes and doubling of the octave. Added rhythmic features do much to subtly enhance the original dance’s courante features, so it seems a little incongruous that this should be followed by three relatively straightforward contreparties as they appear not to progress from the first example. However, this was perhaps by design since their relatively simple structures and keys provide a good basis from which the harpsichordist might begin to deviate from the written material, if not begin to extemporise. It is disappointing that only the Allemande la Vauvert is developed sufficiently to provide a nuanced example of the means by which brisure and added harmonies might be applied to the dances. It is also unfortunate that Le Roux did not include a sarabande among his realised contreparties. They prove to be the most intricate of his genres and since their textures make them ideally suitable for their development as duets, some indication of how to approach them would have been a welcome addition.
By publishing Pieces de Clavessin, Le Roux ensured that they were available mistake-free while also asserting his rights as their composer. It is impossible to say how many copies were produced or how they were received, but the relatively high price of ten livres suggests that the market was relatively exclusive. That we know of only two copies of the 1705 imprint cannot be taken as an indicator of either its sales or popularity, but the lack of extant sources suggests that the original print run was less than the 1,500 copies the privilège permitted. It was, however, a publication that drew the attention of Roger, who was responsible for a wider dissemination than could have been achieved by Le Roux alone. Yet despite the charm and elegance of his music, with just 44 solo pieces to his name Le Roux cannot be regarded as anything other than a minor figure of the Grand Siècle. When Paris was consumed with enthusiasm for Italian composers, he created music of great charm and rich counterpoint in a sophisticated French style. But it is not only the music that is noteworthy since the publication contains underlying pedagogical features that highlight an aspect of music history that is often ignored: teachers of Le Roux’s time left little evidence of their work and this makes his publication all the more extraordinary. As a composer, his diversity is intriguing and his music is appealing; as an educator, his publication is unique and it is because of this that Le Roux is deserving of more recognition than history has thus far provided.
 Le Roux (1705), ii: ‘On a souhaité que je misse le dessus et la basse de chaquun des ces pièces. Cequi sera d’un grand secours a ceux qui voudront chanter et accompagner avant que de les apprendre par tablature, Laquelle deviendra alors tres facille étant prevenus du chant et du mouvement, J’y ay ajouté une contrepartie pour le concert.’ (‘It was hoped that I would provide the treble and the bass of each of the pieces. This will be of great help to those who wish to sing and play accompaniments before learning them from the score, which will become very easy, having reviewed the melody and the rhythm. I have also added a contrepartie for ensemble playing.’)
 ‘Although I never spared any cares or pains in putting my musical compositions into the best condition before they leave my hands, I never intended to expose them to the eyes of the public. However, encouraged by people of great learning and concerned by the coarse mistakes that I have noticed in the copies of my harpsichord pieces that have circulated against my wishes, I have finally resolved to have them engraved and to sound out the taste of the public, who alone can decide the merit of these works.’
 For example, Denis Gaultier (1670 and 1672), Chambonnières (1670), Marin Marais (1686) and Couperin (1713) to name a few.
 The influences demonstrated in Sarabande are discussed under the section A note on performance.
 Clérambault (1704), 1-2 and 15-16.
 For example, François Roberday’s Fugues, et caprices, à quatre parties for organ (Paris, 1660) states that the open score made them suitable to be played on viols, or other similar instruments.
 D-B Ms. Danzig 4230.
 ‘The greater part of these pieces is effective with two harpsichords, one playing the subject and the other playing the contrepartie. An example of this will be found in the six pieces that are at the end of the volume.’
 Le Roux (1705), ii.