For the public reopening of the Royal Opera of Versailles, Philippe Beaussant, musicologist specialized in the xvii^th century, tells the story of the birth of this opera, conceived by Louis XIV and built under Louis XV. Renowned as one of the most beautiful theaters of the court, the Royal Opera of the Palace of Versailles, with its 712 places and acoustically perfect all-wooden auditorium, was one of the most personal delights of the Sun King, an afficiondo of music and dance. The author uses striking anecdotes to chronicle the successive projects that led to the opera, and fit it into a history of the time period's taste. Photos by Philippe Chancel offer an artist's view of this exceptional renovation.