Die Fledermaus is one of the few operatic works to which the phrase "never a dull moment" can be truthfully applied. From the explosive opening of the famous overture - reminiscent of a volley of champagne corks - through the surging energy of the "Fledermaus Waltz" and the many comic numbers, of which the accelerando trio is the finest, up to such huge concerted numbers as the "Duidu" finale to Act II, this is an operetta which almost incarnates nostalgia. Thomson Smillie and David Timson infuse their exploration of Die Fledermaus with as much life as the operetta itself.

La sonnambula was written by Bellini as a vehicle for two of the supreme singers of his age and accordingly is a fine example of the school we call bel canto, where beauty of voice and the virtuosity of the singers is integral to conveying the emotions in the soul of the composer. The fact that Bellini was one of the great melodists, writing long, beautiful vocal lines, that he was a master orchestrator and that he could write stirringly for the chorus all conspire to make La sonnambula extremely enjoyable.

Rossini’s comic operas, like The Barber of Seville, are better known than his tragedies though he wrote in fact many more tragedies than comedies. One of them, his last, William Tell, is actually credited with launching the whole age of Grand Opéra. Tancredi is an early work - indeed his first smash hit - and it established his international fame.

Monteverdi’s Orfeo, first performed in 1607, generates a special excitement because it is the first unquestioned masterpiece of opera. Notable for its precise orchestration and powerful drama it was a groundbreaking work. It concerns the legend of Orpheus, the demigod whose music had the power to conquer the forces of Hell and to bring his wife back, briefly, to life. The extracts used in this introduction are from Naxos’ full recording; it uses authentic period instruments, which serve to evoke the early Baroque period of the opera’s composition.

Pagliacci may be the most completely compelling short opera in the repertory and owes much of its impact to a brilliant story based, it is said, on true life and told through the device of a play-within-a-play. The action is set in Calabria in the deep south of Italy where the jealousies and illicit passions of a troupe of strolling actors precisely intersect with the play they are performing - to both touching and tragic effect.

Dating from the last decade of the 19th century, Pelléas et Mélisande points the way into the 20th century. The score is hauntingly beautiful, but there is more to the work than shifting panels of elusive, impressionistic sound. Debussy retains the text of Maeterlinck’s play, and the linguistic subtleties of the French text are matched perfectly by the musical detail. Taking a little time to explore the romantic, elusive world of this opera is particularly rewarding.

The Flying Dutchman is the perfect opera with which to approach the operatic mountain that is Richard Wagner. It is short, has a great story (the legend of the Dutch captain doomed to sail forever unless redeemed through love), and the striking score has many pre-echoes of Wagner's later great music dramas. It contains wonderful tunes in its arias, ensembles, and big choruses, and the orchestral writing - from the gale that blows out of the Overture to the final theme of "Redemption through Love" - will "blow you away".

Verdi’s Falstaff repays careful study with real pleasure. It is opera’s happiest irony that the great Italian master should cap a career - distinguished for its blood-and-thunder tragic masterpieces - with the greatest comic opera in the Italian repertory. The genius of Shakespeare is harnessed (in a miracle of compression) by master-librettist Boito to give the 80-year-old Verdi a superb libretto, on which he lavished more wonderful tunes than most composers manage in a lifetime.

Il Trovatore has been ruthlessly parodied. It is a tale of murder and mayhem, burned babies, roasted hags, would-be nuns, strolling minstrels, and bad baritones. And indeed the libretto does call for a willing suspension of disbelief. The reward is in the music, a score as prodigally melodic as only the mature Verdi could write: the "Anvil" chorus, the "Miserere" scene, two great tenor arias, a beautiful baritone aria - a richness without embarrassment.

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.

Così Fan Tutte contains some of Mozart’s most sublime music. On one level, the opera is purely a social anecdote about young people falling in and out of love; but Mozart was a supreme sensualist and a great humanist, and invested the tale with all his understanding of humanity and young love. In this title, David Timson refutes the charge that Mozart squandered his genius on a work full of trivial nonsense and proves this "miraculous yet problematic" opera to be a great work of theatre. To listen to this thought-provoking examination of the characters and the music is both thoroughly enriching and great fun.

La Traviata owes its enduring popularity to a superb story of young love and fatal sacrifice, set to music by Italy’s master melodist at the peak of his powers. Interest and poignancy are added by the fact that this is a true story - the baritone ‘heavy’ is Alexander Dumas who wrote The Count of Monte Cristo. But it is the central figure, the heroine Violetta, the archetypal ‘whore with the heart of gold’ who dominates the piece. It is her opera and we love her for it.

Puccini’s swansong has a claim to being the last great popular opera. Its melodies have enchanted audiences since its posthumous premiere in 1926, two years after Puccini’s death. It involves a chilling story of love and cruelty, an intriguing cast of characters against the exotic backdrop of Imperial China, magnificent choruses and ensembles, and dazzling orchestration in an exotic score that comprises a string of remarkable arias - among which the great tenor aria "Nessun dorma" is the jewel. It is more than Puccini’s last opera: It is the last word, in every sense, on Italian opera.

Carmen is among the most popular operas for all the obvious reasons: great characters, a gripping story, and fabulous music. But what sets it on a pinnacle is an amazing combination of three factors: a sizzling Gipsy heroine (one of the most psychologically complex and compelling characters in all theatre), great atmosphere (Spain, hot sun, the bull-ring), and the prodigality of melodic invention - one great tune after another, at least a dozen of which are the staples of Madison Avenue and the animated cartoon.

Many opera-lovers would name The Marriage of Figaro as their favorite opera. It appeals to the most intellectual listener, but also to music-lovers seeking great melodies and ensembles (while it remains accessible through its fascinating plot and memorable characters) and to those seeking only entertainment. One of three operas by Mozart to libretti by Lorenzo da Ponte, it represents one of the pinnacles not just of operatic but of human achievement.