Fidelio is a work like no other. Beethoven's only opera is about the joy of married love - by a man who never knew that pleasure. It is about heroism by a man who was often mean and petty in his human relations; it is about freedom by a man who was a prisoner of his own deafness; and ultimately it is about joy by a man who experienced precious little of it. Maybe there is a divine logic to that: feelings the artist could not experience but could express find their noblest manifestation in music of overwhelming power and majesty. The most popular operas from the early 19th century are Italian - Rossini, Donizetti, Verdi. We know that Fidelio is important because it was Beethoven's only opera, but it is not, on the face of it, as much fun as The Barber of Seville, or Don Pasquale. This is why Thomson Smillie's introduction is so useful. He places the plot and the music against the background of Beethoven's own turbulent life and suddenly we realise the importance and the uplifting nature of the themes he deals with - starting with fidelity, the name of the opera itself. This is a riveting preparation for seeing or hearing the whole opera.