ABC are the first three letters of the Latin alphabet. They may refer to:

Overture (French ouverture; German Ouvertüre, Vorspiel; Italian overtura; i.e. opening) in music is the term originally applied to the instrumental introduction to an opera. During the early Romantic era, composers such as Beethoven and Mendelssohn began to use the term to refer to independent, self-existing instrumental, programmatic works that presaged genres such as the symphonic poem. These were at first no doubt intended to be played at the head of a programme.

The idea of an instrumental opening to opera existed during the 17th century. Peri's Euridice opens with a brief instrumental ritornello, and Monteverdi's L'Orfeo (1607) opens with a toccata, in this case a fanfare for muted trumpets. More important, however, was the Prologue, which comprised sung dialogue between allegorical characters which introduced the over-arching themes of the stories depicted.

As a musical form, however, the so-called French overture begins with the court ballet and operatic overtures of Jean-Baptiste Lully, which he elaborated from a similar, two-section form called Ouverture, found in the French ballets de cour as early as 1640. This French overture consists of a slow introduction in a marked "dotted rhythm" (i.e., exaggerated iambic, if the first chord is disregarded), followed by a lively movement in fugato style. The overture was frequently followed by a series of dance tunes before the curtain rose, and would often return following the Prologue to introduce the action proper. This ouverture style was also used in English opera, most notably in Henry Purcell's Dido and Æneas. Its distinctive rhythmic profile and function thus led to the French overture style as found in the works of late Baroque composers such as Johann Sebastian Bach. The style is most often used in preludes to suites, and can be found in non-staged vocal works such as cantatas, for example in the opening chorus of Bach's cantata Nun komm, der Heiden Heiland, BWV 61.

William Tell (in the four languages of Switzerland: German: Wilhelm Tell; French: Guillaume Tell; Italian: Guglielmo Tell; Romansh: Guglielm Tell) is a folk hero of Switzerland. His legend is recorded in a late 15th-century Swiss chronicle.

It is set in the period of the original foundation of the Old Swiss Confederacy in the early 14th century. According to the legend, Tell — an expert marksman with the crossbow — assassinated Gessler, a tyrannical reeve of Habsburg Austria positioned in Altdorf, Uri.

Along with Arnold Winkelried, Tell is a central figure in Swiss patriotism as it was constructed during the Restoration of the Confederacy after the Napoleonic era.

There are several accounts of the Tell legend. The earliest sources give an account of the apple-shot, Tell's escape and the ensuing rebellion. The assassination of Gessler is not mentioned in the Tellenlied, but is already present in the White Book of Sarnen account.

The legend as told by Tschudi (ca. 1570) goes as follows: William Tell, who originally came from Bürglen, was known as a strong man and an expert shot with the crossbow. In his time, the Habsburg emperors of Austria were seeking to dominate Uri. Albrecht (or Hermann) Gessler, the newly appointed Austrian Vogt of Altdorf, raised a pole in the village's central square, hung his hat on top of it, and demanded that all the townsfolk bow before the hat. On 18 November 1307, Tell visited Altdorf with his young son and passed by the hat, publicly refusing to bow to it, and so was arrested. Gessler — intrigued by Tell's famed marksmanship, yet resentful of his defiance — devised a cruel punishment: Tell and his son would be executed, but he could redeem his life by shooting an apple off the head of his son, Walter, in a single attempt. Tell split the apple with a bolt from his crossbow.

The Sydney Symphony Orchestra (abbreviation – SSO), commonly known as the Sydney Symphony, is an Australian symphony orchestra based in Sydney. It has the unique privilege of having the Sydney Opera House as its home concert hall. The orchestra's current chief conductor is Vladimir Ashkenazy. His term will conclude in 2013, and David Robertson will succeed him from 2014.

The Sydney Symphony is an icon of the Sydney cultural scene, performing around 150 concerts a year to a combined annual audience of more than 350,000. The regular subscription concert series are mostly performed at the Sydney Opera House but other venues around Sydney are used as well, including the City Recital Hall at Angel Place and the Sydney Town Hall. The Town Hall was the home of the orchestra until the opening of the Opera House in 1973. Since then, most concerts have been taking place in the Opera House's Concert Hall (capacity: 2,679 seats).

A major annual event for the orchestra is Symphony in the Domain, a free evening outdoor picnic concert held in the summer month of January in the large city park known as The Domain. This event draws audiences of over 80,000 and is a long-established part of the Sydney summer cultural calendar.

Patrick Thomas MBE (born 1 June 1932) is an Australian conductor.

For a period of almost 35 years he conducted hundreds of performances across Australia in just about every centre where the various state symphony orchestras ventured, and introduced music to virtually a whole generation of young Australians through his popular and distinctive schools concerts. He held a succession of important posts with four of Australia's major ABC orchestras and the specially created position of ABC Federal Conductor-in-Residence as well as conducting the Australian Opera and the Australian Ballet. He also conducted the ABC's radio chorus, the Adelaide Singers.

Overseas, he appeared in 12 countries as Guest Conductor of such orchestras as the Moscow Philharmonic Orchestra, the Hallé Orchestra, Bavarian Radio Orchestra, Polish National Radio and Television Orchestra, Munich Philharmonic, BBC Symphony Orchestra, CBC Symphony Orchestra, Prague Radio Orchestra, and many others in New Zealand, the Czech Republic, Bulgaria and South Africa. Other facets of his diverse career included those of concert, radio and television presenter and interviewer.