Medieval (c.1150 - c.1400)

This is the first period where we can be fairly certain how a great deal of the music which has survived actually sounded. The earliest written secular music dates from the 12th century troubadours, but most notated manuscripts emanate from places of learning usually connected with the church, and therefore have a religious basis.

Gregorian chant and plainsong which are monodic (i.e. written as one musical line) gradually developed during the 11th through 13th centuries into organum (i.e. two or three lines moving simultaneously but independently, representing the beginnings of harmony). Organum was, however, initially stifled by rigid rules governing melody and rhythm, which led ultimately to the so-called Ars Nova period of the 14th century, principally represented by the composers de Vitry, Machaut, and Landini.

Renaissance (c.1400 - c.1600)

The fifteenth century witnessed vast increasesin musical freedom, most particularly in terms of what is actually perceived as harmony and polyphony (the simultaneous movement of two or three interrelated parts). Composers were still almost entirely devoted to choral writing, and the few instrumental compositions which have survived often create the impression of really being vocal works, minus the words. There was, however, obvious delight in textural variety and contrast.. The four most influential composers of the fifteenth century were Dunstable, Ockeghem, Despres and Dufay.

The second half of the 16th century witnessed the beginnings of the tradition which many music lovers readily associate with the normal feel of 'classical' music. Composers Ggadually moved away from the modal system of harmony which had predominated for over 300 years (which sounds archaic to some modern ears), towards the organisation of their work into major and minor scales,imparting the strong sensation of each piece having a definite tonal centre or 'key'.

This was also a golden period for choral composition, as a seemingly endless flow of a capella (unaccompanied) masses, motets, anthems, psalms and madrigals flowed from the pens of the masters of the age. In addition, instrumental music came into its own for the first time, especially keyboard music in the form of fantasias, variations, and dance movements (galliards, pavanes etc.). Composers of particular note include Dowland, Tallis, Byrd, Gibbons, Frescobaldi, Palestrina, Victoria, Lassus, Lobo, Cardoso and Gesualdo.

Baroque (c.1600 - c.1750)

During the Baroque period, the foundations were laid for the next 300 years of musical expression: the idea of the modern orchestra was born, along with opera (including the overture, prelude, aria, recitative and chorus), the concerto, sonata, and modern cantata. The soft-grained viol string family of the Renaissance was gradually replaced by the bolder violin, viola and cello, the harpsichord was invented, and important advances were made in all instrumental groups.

Until about 1700, the old modal system still exerted itself by colouring certain melodic lines or chord progressions, but f the modern harmonic system based upon the major and minor scales was in use throughout Europe. Choral music no longer dominated, and as composers turned more and more to writing idiomatic instrumental works for ensembles of increasing colour and variety, so 'classical' music (as opposed to 'popular') gradually began to work its way into the very fabric of society, being played outdoors, at dinner parties or at special functions. Every wealthy lady would have a spinet to play, and the rich employed musicians to play at meal-times. This was called Tafelmusik in Germany, of which Telemann was perhaps the most famous composer.

Of the many 17th century composers who paved the way for the popular explosion of 'classical' music, the following were outstanding: Monteverdi, Corelli, Allessandro Scarlatti, Schutz, Buxtehude, Purcell and Lully. Yet the most popular composers of the period, those who seem to define by their very names the sound of Baroque music at its most colourful and sophisticated, are Johann Sebastian Bach, Handel, Rameau, François Couperin, Domenico Scarlatti, and Vivaldi, all of them at their creative peak during the first half of the 18th century.

Classical (c.1750 - c.1830)

The Baroque era witnessed the creation of a number of musical genres which would maintain a hold on composition for years to come, yet it was the Classical period which saw the introduction of a form which has dominated instrumental composition to the present day: sonata form. With it came the development of the modern concerto, symphony, sonata, trio and quartet to a new peak of structural and expressive refinement. If Baroque music is notable for its textural intricacy, then the Classical period is characterised by a near-obsession with structural clarity.

The seeds of the Classical age were sown by a number of composers whose names are now largely forgotten, such as Schobert and Honnauer, as well as more historically respected names like Gluck, Boccherini and at least three of Johann Sebastian Bach's sons: Carl Phillip Emmanuel, Wilhelm Friedmann and Johann Christian (the so-called 'London' Bach). They were representative of a period which is described as rococo or galante, the former implying a gradual move away from the artifice of the High Baroque, the latter an entirely novel style based on symmetry and sensibility, which dominated the music of the latter half of the 18th century throughcomposers of extraordinary significance: Haydn, Mozart. Beethoven and Schubert.

Early Romantic (c.1830 - c.1860)

As the Classical period reached its zenith, it become increasingly clear that the amount and intensity of expression composers were seeking to achieve was beginning to go beyond that which a Classically sized orchestra/piano could possibly encompass. The next period in musical history therefore found composers attempting to balance the expressive and the formal in music with a variety of approaches which would have left composers of any previous age utterly bewildered. As the musical map opened up, with nationalist schools beginning to emerge, the search for originality and individuality of expression was paramount.

The Romantic era was the golden age of the virtuoso, where the most fiendishly difficult music would be performed with nonchalant ease, and the most innocuous theme in a composition would be developed at great length for the enjoyment of the adoring audience. The emotional range of music during this period was considerably widened, as was its harmonic vocabulary and the range and number of instruments which might be called upon to play it. Music often had a 'programme' or story-line attached to it, sometimes of a tragic or despairing nature, occasionally representing such natural phenomena as rivers or galloping horses. The next hundred years would find composers either embracing whole-heartedly the ideals of Romanticism, or reacting against them.

Of the early Romantic composers, two Nationalists deserve special mention, the Russian Glinka and the Bohemian Smetana. However, the six leading composers of the age were undoubtedly Berlioz, Chopin, Mendelssohn, Schumann, Liszt and Verdi.

Late Romantic (c.1860 - c.1920)

With the honourable exceptions of Brahms and Bruckner, composers of this period shared a general tendency towards allowing their natural inspiration free rein, often pacing their compositions more in terms of their emotional content and dramatic continuity rather than organic structural growth. The era was highlighted by the extraordinarily rapid appearance of the national schools,but the fragmentation of this basic style, as more and more composers joined vaious 'schools' of composition, brought about the eventual end of Romanticism.

This period, so rich in famous names and compositions, exploded with works by Albéniz, Bizet ,Debussy, Franck, Grieg, Holst, Mahler, Rachmaninov, Ravel, Respighi, Rimsky-Korsakov, Saint-Saëns, Satie, Sibelius, Johann and Richard Strauss, Tchaikovsky and Wagner.

Post 'Great War' Years (c.1920 - Present)

This period is undoubtedly the most bewildering of all, with composers pulling in various apparently contradictory and opposing directions. Typical of the dilemma were the Austrians, Webern and Lehar. At a time when Webern as experimenting with the highly compressed and advanced form known as serial structure, Lehar was still indulging in an operetta style which would not have seemed out of place over half a century beforehand.

So diverse are the styles adopted throughout the greater part of the 20th century that only by experimentation can listeners discover for themselves whether certain composers are to their particular taste or not. A representative list of popular compsers incude Britten, Copland, Gershwin, Orff, Prokofiev, Shostakovich and Stravinsky.