The sound of rock often revolves around the electric guitar or acoustic guitar, and it uses a strong back beat laid down by a rhythm section of electric bass guitar, drums, and keyboard instruments such as organ, piano, or, since the 1970s, digital synthesizers. Along with the guitar or keyboards, saxophone and blues-style harmonica are sometimes used as soloing instruments. In its “purest form”, it “has three chords, a strong, insistent back beat, and a catchy melody.”^[1]

In the late 1960s and early 1970s, rock music developed different subgenres. When it was blended with folk music it created folk rock, with blues to create blues-rock and with jazz, to create jazz-rock fusion. In the 1970s, rock incorporated influences from soul, funk, and latin music. Also in the 1970s, rock developed a number of subgenres, such as soft rock, glam rock, heavy metal, hard rock, progressive rock, and punk rock. Rock subgenres that emerged in the 1980s included New Wave, hardcore punk and alternative rock. In the 1990s, rock subgenres included grunge, Britpop, indie rock, and nu metal.

A group of musicians specializing in rock music is called a rock band or rock group. Many rock groups consist of an electric guitarist, lead singer, bass guitarist, and a drummer, forming a quartet. Some groups omit one or more of these roles and/or utilize a lead singer who plays an instrument while singing, sometimes forming a trio or duo; others include additional musicians such as one or two rhythm guitarists and/or a keyboardist. More rarely, groups also utilize stringed instruments such as violins or cellos, or horn sections of saxophones, trumpets or trombones.

Byzantine music the music of the Byzantine Empire composed to Greek texts as ceremonial, festival, or church music.

Long thought to be only a further development of ancient Greek music, Byzantine music is now regarded as an independent musical culture, with elements derived from Syrian and Hebrew as well as Greek sources. Its beginnings are dated by some scholars to the 4th cent., after the founding of the Eastern Empire by Constantine I.

Although two Greek instruments, the kithara and the aulos, were used, the principal instrument of Byzantium was the organ. No purely instrumental music is extant, however, and the exact nature of the instrumental accompaniment of vocal music is not certain. The eight Byzantine echoi (singular echos ) correspond roughly to the eight modes of plainsong , but they were groups of melodies made of certain definite formulas. The Byzantine music that survives is all sacred, with the exception of some acclamations for the emperor. Byzantine chant was monodic, in free rhythm, and often attempted to depict melodically the meaning of the words. The language was Greek.

The Byzantine hymn, of which there were three types, was the greatest contribution of this culture. The troparion, a hymn, was inserted between the verses of the Psalms, and eventually the troparia overshadowed the Psalms. The origin of the kontakion, a hymn important in the 6th and 9th cent., is ascribed to Romanus, active during the reign of Anastasius I; it consisted of 18 or 24 strophes all in similar meter, with a contrasting introductory strophe. The subject matter was usually biblical. Often an acrostic is formed by the first letter of each stanza.

The time of Romanus and of Sergius (fl. early 7th cent.) is called the golden age of Byzantine music. In the 8th cent. the outstanding hymn writers were St. John of Damascus and Cosmas of Jerusalem. The chief type of hymn was the kanon, a series of odes, theoretically nine but often only eight in number, referring to the nine canticles of the Old and New Testaments. Until the 9th cent., poet and composer were always one; later, hymns were set to already existing melodies. With the codification of the Greek liturgy in the 11th cent. came a general decline in hymnody. Musical activity ceased with the fall of Constantinople (1453). Russian chant, the chant of the modern Greek Orthodox Church, and to a small extent Gregorian chant all owe something to Byzantine chant.

Byzantine notation was originally only a system of ekphonetic symbols serving to remind a singer of a melody he already knew. Neumes derived from the ekphonetic notation were in use from c.950 until 1200. From 1110 to 1450 a staffless notation was in use that indicated the echos, starting note, and subsequent intervals of a melody. It is largely decipherable today. Signs were added to it in the centuries that followed. The notation used in the Greek Church today was devised in the 19th cent. by Chrysanthus, a Greek archimandrite, because of the confusion in deciphering the manuscripts of early Byzantine music.

Bibliography: See G. Reese, Music in the Middle Ages (1940); studies of Byzantine music and hymnography by S. I. Savas (1965) and A. L. Burkhalter (1968).

In music history, the term “Romanticism” refers to 19^th century creations. It is the continuance and evolution of Classicism’s music language and forms to the extend that justifies the integrated study of both eras. Romanticism refers to 19^th century creations, from Schubert to Strauss, while during this period the prevailing tendencies are at times romantic and at times classical. Music tends to express the emotions of each specific composer.

• Early Romantic era 1800 – 30: Vienna is the centre of developments. The first work to acquire the wider public’ s response with references to folk characters, nature, superstitions and miracles was “Der Freischütz” by Carl Maria von Weber (1786 – 1826). Franz Schubert’s works expressed the poetic spirit of the time and the whimsical music of Gioachino Rossini (1792 – 1868) contradicted Beethoven’s meaningful music.

• The climax of Romanticism 1830 – 50: Paris is the centre of developments and music receives new influences from the French literary Romanticism. The spirit of the time is reflected in Hector Berlioz’s “Symphonie fantastique”. Nicolo Pagannini’s and Franz Lizst’s exceptional skills also characterize this era. Moreover, this era is characterized by the development of the magical sound of Frederic Chopin, the poetic music and smart critique of Robert Schumann, the romantic classicism of Felix Mendelssohn, the romantic opera of Richard Wagner, the appealing operas of Giussepe Verdi and Meyerbeer.

• Late Romantic era 1850 – 1890: Following the deaths of Mendelssohn, Chopin and Schumann, a new era begins with Lizst’s symphonic poetry, Wagner’s musical dramas and Verdi’s early operas. A new generation of creators like Cesar Franck, Anton Bruckner and Johannes Brahms also appears in this period. Formalistic and expressionistic aesthetics marched together with national colors adding late romantic characteristics to music.

Around 1890 Gustav Mahler, Claude Debussy and Richard Strauss appear in the music scene and through their works they drive new tendencies to the extremes. At the same time, French impressionism appears as a modernistic phenomenon of late Romanticism. The end of the Romantic period is marked by Schonberg’s transition to atonality at