La Bohème is one of the three operas - the others are Carmen and Aida - believed to be the most popular ever written. In the case of La Bohème the reason is that it virtually defines the term "romantic". The poignant story of Mimì and Rodolfo is told in music of such tender beauty, allied, as always, to Puccini’s intuition of what works in the theatre. The result is an opera that readily appeals to our emotions and senses.

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.

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.

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.

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.

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.

The Barber of Seville is Rossini’s most popular opera. Its effervescent overture (written originally for another work!) presents a perfect platform for the amusing plot in which the barber, Figaro, stage-manages a romance between Count Almaviva and Rosina, and puts to flight the old suitor, Dr Bartolo. "Largo al Factotum" is one of the most popular arias in opera - nearly 200 years after its first performance it is still one of the great show-stoppers.

Don Giovanni has long been regarded as Mozart’s supreme theatrical achievement. The subject seems unpromising - the last day in the life of the notorious womanizer Don Juan - but the skill of the librettist allied to the genius of Mozart at the very peak of his powers has created a work which is not only highly entertaining but reflects an incredible understanding of the human condition.

Rigoletto is simply wonderful entertainment with superb music. It is also much more - a daring (for its time) attack on aristocratic privilege, a tender love story, and an impassioned appeal on behalf of the disadvantaged, all set to music of such wealth and beauty that, with its sister operas La traviata and Il trovatore, it has defined Italian opera for 150 years. Overcoming initial trouble with the censors, Verdi's Rigoletto was a smash hit at its premiere and has not been out of the repertoire since. It’s not hard to see why.

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.

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.

Cavalleria rusticana is the short opera that has all the elements of a grand opera compressed into a single highly dramatic time span. The story of love, lust, blood-feud, and betrayal played out against the pageantry of the Easter celebrations in a Sicilian village delivers an emotional wallop because of the youthful vigor and musical wealth of its great score which includes the glorious "Easter Hymn" and the deeply moving "Intermezzo". Mascagni was never to repeat his youthful success but this brief work is enough to ensure his immortality.

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.

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.