An uninspiring cover and title do inadequate justice to this exceptionally lovely concert and fascinating documentary about the Petit Théâtre, a little-known 18th-century gem concealed in Marie-Antoinette's private estate, the Trianon, annexed to Versailles. A lover of opera and theatre, and keen to participate in plays and operas, Marie-Antoinette decided to build a small private theatre. Miraculously, the wood and pasteboard theatre has survived. Its modest-size stage, intimate orchestra pit and mechanical scenery have been carefully preserved and restored. A semi-staged concert by Belgian group Les Agrémens gives us a privileged glimpse inside this carefully controlled “Baroque” theatre which is rarely accessible to the public.

A series of superb arias and vibrant orchestral interludes by André-Ernest-Modeste Grétry and François-Joseph Gossec (two of Marie-Antoinette's favourite composers) reveal superb acoustics. Grétry's stock rises particularly high thanks to Sophie Karthäuser's gorgeous yet dramatic performances. Forestage in modern concert gown, Karthäuser eyeballs the select small audience throughout her engrossing arias, her melting timbre and articulate coloratura reminding me of Sylvia McNair at the peak of her powers. The spectacular aria “Frà l'orror della tempesta”, sung by an Italian slave in La caravane du Caire (Fontainebleau, 1783), is a colossal simile aria in which Grétry spreads his wings in the full-blown Italian heroic style. Baritone Pierre-Yves Pruvot is less interesting to watch than Karthäuser; his solid performance of excerpts from the tragédie lyrique Sabinus (Versailles, 1773) suggests that Gossec's operatic music is more laboured than Grétry's, but several zesty performances of Gossec's inventive orchestral music are a wonderful enhancement to some transfixing mechanical scene changes.