Defined as a time period in the history of western music, the Classical era begins about 1735 and ends around 1825, overlapping a little with the surrounding periods of late Baroque and early Romantic music. What does the word "Classical" mean in this context? The music has little to do with the classical civilizations of ancient Greece and Rome, though a major revival of their aesthetics and architecture occurred in the 18th century, and associations were made by later writers in an attempt to portray the greatest composers as almost Olympian in stature. Also, the sense of the word "Classical" is narrower than today's popular meaning, which includes Medieval, Renaissance, Baroque, Romantic, Modern, and Contemporary categories as well.

The key to understanding the early development of Classical music in its time period lies with the appearance of a particular musical style, one that originally attracted the terms Galant, Rococo, Empfindsamer Stil ("sensitive style"), and other descriptive words that emphasized its surface beauty, formal balance, refined expression, diatonic harmonies, and clear melodies, as opposed to the rugged, complicated, and passionate counterpoint of the Baroque. Classical era composers seem now to embody the height of elegance, but in their own day they were actually part of a movement that prized naturalness and simplicity over intellectuality and elaboration.

Thanks to the mighty Viennese triumvirate of Franz Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig van Beethoven, listeners tend to think of Classical music as essentially Austrian. But its origins were actually Italian. The beginnings of true Classical style may be traced to Bologna, where composer Francesco Durante began to impart to his students an aesthetic of radical simplification. One of Durante's pupils, Giovanni Pergolesi (left) arrived at a clear-cut and then highly controversial style that stripped away practically all counterpoint in favor of thin textures and sprightly melodies. Pergolesi's Stabat Mater of 1736 replaced the version written in 1714 by Domenico Scarlatti; and while Pergolesi's music sounded naked in comparison to Scarlatti's ornate setting, its simplicity and emotional impact marked something new.

Soon, Italian composers and the Germans who closely observed them devised a new form that allowed them to expand their ideas into the symphony. Originally conceived as a brief prelude to a vocal cantata or opera, the symphony or sinfonia began to take on a life of its own as a type of concert entertainment played by a court orchestra. Although Giovanni Battista Sammartini is generally credited as the first composer to write true Classical symphonies, the Viennese composer Georg Matthias Monn may have beaten him by a couple of years.

C.P.E. BachReflected even in the work of older Baroque composers, such as Georg Philipp Telemann, who adapted to it late in life, the new Classical style finally moved to center stage in European music around 1750. Several of its most celebrated early practitioners were sons of the king of Baroque composers, Johann Sebastian Bach. Carl Philipp Emanuel Bach (right) spent many years working for the music-loving King of Prussia, Frederick the Great. C.P.E. Bach seems to have assimilated the Italian innovations very early on, at least by 1738. He inherited a certain bent toward drama and complexity from his father, and when these qualities encountered the new styles, highly unusual combinations resulted. C.P.E. Bach associated with writers such as Friedrich Klopstock, who developed the overheated literary style known as Sturm und Drang (storm and stress), and he employed a musical style to match: the Empfindsamer Stil, which exerted a strong influence over Haydn.

F.J. Haydn
A student of the Italian Nicola Porpora, Haydn (left) joined the service of the powerful Austro-Hungarian Eszterházy family in 1759. Polite and industrious, Haydn worked hard for three decades, creating, rehearsing, and performing high-quality music for his patrons. As he turned out symphony after symphony (108 in all), Haydn developed procedures that coalesced into what became known sonata-allegro form. Put simply, this meant that a movement often consisted of connected sections -- an exposition of themes, a development section, a recapitulation, and a coda -- marked by modulations into different keys. Haydn revolutionized the symphony by applying the sonata-allegro principle to it, setting the typical number of movements at four: a fast first movement, a moderately slow second movement, a minuet, and a finale. Haydn is also credited with standardizing the string quartet: two violins, a viola, and a cello. Isolated at the Eszterházy estate for much of his career, Haydn hardly realized what a celebrity he was: his works were played everywhere and were eagerly studied by other composers, perhaps most eagerly of all by Mozart.

W.A. MozartA child prodigy, Mozart was tutored in composition by his father, Leopold Mozart. Strongly affected early on by the work of the Bolognese teacher Padre Martini's most brilliant student, Johann Christian Bach, Mozart combined several talents into a popular and moving style that was so musically sound it had the much-prized quality of seeming effortlessness. Perhaps Mozart's greatest contributions came in opera, but he also made lasting contributions to the symphony, chamber music, keyboard music, and choral music. Mozart's reputation does not rest on formal innovations of the kind that Haydn introduced; rather it is the mastery, effectiveness, and sheer beauty of his work that place it in a class by itself. Contrary to popular accounts, his early death in 1791 was widely noted, observed and mourned, and it stirred speculation that musical change was in the wind.

L. v. BeethovenIndeed, Beethoven was coming of age as the horrors of the French Revolution and its Reign of Terror challenged the notion that the quest for democracy would lead to a halcyon the Age of Reason. In 1792 Beethoven moved to Vienna from Bonn and soon established himself as the natural heir to Mozart and the aging Haydn. By the end of the decade, however, Beethoven was breaking down the neat boundaries of Classical forms. Broadly speaking, Beethoven united Classical ideals of abstract form and balance with the concerns that would dominate the Romantic century to come: human nature and experience, the social contract, and the power of the natural world. When Beethoven's 50-minute "Eroica" Symphony was premiered in 1803, critics and composers alike thought that he had lost his mind. Long or short, his works took on a scope and intensity that seemed at odds with Classical style, even as they maintained its logic. Beethoven redefined the piano sonata as a powerful form of individual expression, wrote string quartets of unparalleled complexity, and turned the concerto into a virtuoso essay on the theme of the individual versus the multitude. With the group of songs called An die ferne Geliebte, he created the song cycle, a genre that was the very essence of emotional subjectivity.

By the end of the 1810s, younger composers such as Franz Schubert and Franz Berwald began to take the hint that Beethoven was on the right track. In 1824, Beethoven's Ninth Symphony, more than an hour in length, became the new model of what a symphony could be, embracing an expanded orchestra, a chorus, four vocal soloists, and a vision of a new world.

During the Classical era, composers began to exert more influence over performances of their music. Haydn suggested at the start of the published score of his "Oxford" Symphony that if the work were given even one rehearsal, it would be better served than if it were read cold at the concert. No composer had made such a specification before. Gradually, expression marks and specified tempos in both written and published scores grew more prominent. Beethoven began employing metronome markings to set the tempos of his music. Percussion and certain wind parts, previously indicated sketchily if present at all, now were written out. The clarinet, the bassoon, and eventually the trombone emerged as important instruments during the period.

J.C. Bach
The symphony, the string quartet, and the solo concerto came to full maturity, while the multiple-instrument concertos of the Baroque and the early Classical periods declined in importance. J.S. Bach had arranged his keyboard concertos from violin works, and Vivaldi never wrote any keyboard concertos at all. In comparison, by 1765, Bach's sons Carl Phillip Emanuel and Johann Christian (right) had each already written dozens of them. The pianoforte (or piano) was invented by Bartolomeo Cristofori in 1729, was refined, and became readily available by about 1770. Soon the harpsichord would seem a quaint relic.

One defining feature of Classical music was the rise of comic opera, for opera would have been central to an 18th century music enthusiast's experiences. Pergolesi's intermezzo La serva padrona was the pioneering work in this style, and its central story of a servant outwitting a master would set a dangerous precedent for works to come, most importantly Mozart's The Marriage of Figaro. Early comic operas portrayed realistic characters in familiar situations and did away with the old Greco-Roman pantheon of mythic figures (Baroque composers actually turned to the Greek and Roman classics more often than Classical composers did).

C.W. GluckSerious opera continued to use mythological and antique settings, but change came to that genre as well. Christoph Willibald Gluck (left) supplied his 1762 opera Orfeo ed Euridice with music that was simple and clear-textured, and for the first time arias and recitatives were married into one harmonious unit. The libretto was structured for dramatic effect, avoiding heavy metaphorical allusions and references to obscure mythic figures having nothing to do with the story at hand. Gluck's reforms were not to everyone's taste, but in time they took hold. Mozart's operas were prime examples of the new directness the reforms made possible. Don Giovanni, his tale of Don Juan's carousing ways and grim demise, would have been unthinkable at the dawn of the Classical era.

Getting a handle on even the essential works of Haydn, Mozart, and Beethoven provides more than enough listening for any beginner, and compositions by some of the "second rank," such as Karl Ditters von Dittersdorf or Carl Stamitz, may seem more like work than pleasure. But if you explore a little deeper, you'll find composers from all over Europe who were touched by the new currents and made something distinctive from them: Juan Arriaga and Carlos Baguer from Spain; the Franco-German Franz Ignaz Beck; the keyboard virtuosos Muzio Clementi (from Italy) and Jan Ladislav Dussek (a well-traveled Czech), both of whom heavily influenced Beethoven; the German-born Swede Joseph Martin Kraus; the Czech symphonist Johann Baptist Vanhal; and the operatic and church composer Luigi Cherubini (Beethoven's own favorite among his contemporaries). All these composers belong to the Classical era, and all are interesting and enjoyable on their own terms.