The "authentic performance" approach generally familiar from the 1970s onward, plus skillful restoration of original instruments by makers such as Rémi Dubois (Verviers, Belgium), has made it possible to hear works such as Chédeville's "Pastor Fido" (based on Vivaldi's "The Four Seasons"), chamber-music by Boismortier and even Rameau's opéra-ballet "Les Fêtes d'Hébé" in their original form. Chalumeaux (chanters) The frontispiece in Borjon de Scellery's Traité (1672) shows a shepherd surrounded by a number of instruments. They include an early musette, with a single chalumeau that appears to have six finger-holes and no keys. The first full-page plate then illustrates a chalumeau with seven finger-holes and three keys, giving a range of one octave. The second full-page plate illustrates a more developed form of the musette, where a grand chalumeau with five keys is complemented by a petit chalumeau with six keys. Jacques Hotteterre's Méthode (1738) illustrates the most usual final form of the instrument; the six-key petit chalumeau is the same as de Scellery's, but the grand chalumeau now has seven keys. The petit chalumeau, as already mentioned, was added by Martin Hotteterre; though physically connected to the grand chalumeau, and sharing the same wind-supply from the bellows, it has its own double reed and functions as a separate instrument. The lowest note on the petit chalumeau is an A flat a semi-tone below the higher A on the grand chalumeau, and keeping the two chalumeaux in tune and in balance is one of the difficulties of the instrument. The grand chalumeau is open, so it always sounds. The petit chalumeau is closed, like the Northumbrian smallpipes, so it sounds only when a hole is opened or a key is pressed. The fingering system on both chalumeaux is "closed", meaning that (except while playing some ornaments) only one hole at a time is opened. Bourdons (drones) Following the principle of the rackett and the bassoon, the short cylinder of the musette drone contains airways that double back on themselves. Openings in each airway (the equivalent of finger-holes) are uncovered by moving layettes (sliders) fixed in four coulisses (runners). The two lowest notes use the same airway, so cannot be played together. The earliest musettes had up to nine coulisses and twelve layettes, so that you could play music in a range of modes and always have a drone using the home-note of the mode. As the chalumeaux developed and became