Time signature in the context of Allegro (music)

Music theory is the study of theoretical frameworks for understanding the practices and possibilities of music. The Oxford Companion to Music describes three interrelated uses of the term "music theory": The first is the "rudiments", that are needed to understand music notation (key signatures, time signatures, and rhythmic notation); the second is learning scholars' views on music from antiquity to the present; the third is a sub-topic of musicology that "seeks to define processes and general principles in music". The musicological approach to theory differs from music analysis "in that it takes as its starting-point not the individual work or performance but the fundamental materials from which it is built."

Music theory is frequently concerned with describing how musicians and composers make music, including tuning systems and composition methods among other topics. Because of the ever-expanding conception of what constitutes music, a more inclusive definition could be the consideration of any sonic phenomena, including silence. This is not an absolute guideline, however; for example, the study of "music" in the Quadrivium liberal arts university curriculum, that was common in medieval Europe, was an abstract system of proportions that was carefully studied at a distance from actual musical practice. But this medieval discipline became the basis for tuning systems in later centuries and is generally included in modern scholarship on the history of music theory.

Rock music is a genre of popular music that originated in the United States as "rock and roll" in the late 1940s and early 1950s, developing into a range of styles from the mid-1960s, primarily in the United States and United Kingdom. It has its roots in rock and roll, a style that drew from the black musical genres of blues and rhythm and blues, as well as from country music. Rock also drew strongly from genres such as electric blues and folk, and incorporated influences from jazz and other styles. Rock is typically centered on the electric guitar, usually as part of a rock group with electric bass guitar, drums, and one or more singers.

Usually, rock is song-based music with a
₄ time signature and using a verse–chorus form; however, the genre has become extremely diverse. Like pop music, lyrics often stress romantic love but also address a wide variety of other themes that are frequently social or political. Rock was the most popular genre of music in the U.S. and much of the western world from the 1960s up to the 2010s.

In musical terminology, tempo (Italian for 'time'; plural 'tempos', or tempi from the Italian plural), measured in beats per minute, is the speed or pace of a given composition, and is often also an indication of the composition's character or atmosphere. In classical music, tempo is typically indicated with an instruction at the start of a piece (often using conventional Italian terms) and, if a specific metrical pace is desired, is usually measured in beats per minute (bpm or BPM). In modern classical compositions, a "metronome mark" in beats per minute, indicating only measured speed and not any form of expression, may supplement or replace the normal tempo marking, while in modern genres like electronic dance music, tempo will typically simply be stated in bpm.

Tempo (the underlying pulse of the music) is one of the three factors that give a piece of music its texture. The others are meter, which is indicated by a time signature, and articulation, which determines how each note is sounded and how notes are grouped into larger units. While the ability to hold a steady tempo is a vital skill for a musical performer, tempo is malleable. Depending on the genre of a piece of music and the performers' interpretation, a piece may be played with slight variations in tempo, known as tempo rubato, or significant variations. In ensembles, the tempo is often maintained by having players synchronise with a conductor or with a specific instrumentalist, for instance the first violin or the drummer.

In musical notation, a bar (or measure) is a segment of music bounded by vertical lines, known as bar lines (or barlines), usually indicating one or more recurring beats. The length of the bar, measured by the number of note values it contains, is normally indicated by the time signature.

In music and music theory, the beat is the basic unit of time, the pulse (regularly repeating event), of the mensural level (or beat level). The beat is often defined as the rhythm listeners would tap their toes to when listening to a piece of music, or the numbers a musician counts while performing, though in practice this may be technically incorrect (often the first multiple level). In popular use, beat can refer to a variety of related concepts, including pulse, tempo, meter, specific rhythms, and groove.

Rhythm in music is characterized by a repeating sequence of stressed and unstressed beats (often called "strong" and "weak") and divided into bars organized by time signature and tempo indications.

Music theory is the study of theoretical frameworks for understanding the practices and possibilities of music. The Oxford Companion to Music describes three interrelated uses of the term "music theory": The first refers to the "rudiments" needed to understand music notation such as key signatures, time signatures, and rhythmic notation; the second is a study of scholars' views on music from antiquity to the present; the third is a sub-topic of musicology that "seeks to define processes and general principles in music". The musicological approach to theory differs from musical analysis "in that it takes as its starting-point not the individual work or performance but the fundamental materials from which it is built."

Music theory is frequently concerned with describing how musicians and composers make music, including tuning systems and composition methods among other topics. Because of the ever-expanding conception of what constitutes music, a more inclusive definition could be the consideration of any sonic phenomena, including silence. This is not an absolute guideline, however; for example, the study of "music" in the Quadrivium liberal arts university curriculum, that was common in medieval Europe, was an abstract system of proportions that was carefully studied at a distance from actual musical practice. But this medieval discipline became the basis for tuning systems in later centuries and is generally included in modern scholarship on the history of music theory.

Alla breve [alla ˈbrɛːve] – also known as cut time or cut common time – is a musical meter notated by the time signature symbol (a C) with a vertical line through it, which is the equivalent of
₂. The term is Italian for "on the breve", originally meaning that the beat was counted on the breve (double whole note).

Alla breve is a "simple-duple meter with a half-note pulse". The note denomination that represents one beat is the minim or half-note. There are two of these per bar, so that the time signature
₂ may be interpreted as "two minim beats per bar". Alternatively this is read as two beats per measure, where the half note gets the beat.

Four-on-the-floor (or four-to-the-floor) is a rhythm used primarily in dance genres such as disco and electronic dance music. It is a steady, uniformly accented beat in
₄ time in which the bass drum is hit on every beat (1, 2, 3, 4).This was popularized in the disco music of the 1970sand the term four-on-the-floor was widely used in that era, since on a drum set, the beat is played with the pedal-operated, drum-kit bass drum.

Four on the floor was common in jazz drumming until bebop styles expanded rhythmic roles beyond the basics in the 1940s. Garage rock bands of the 1960s such as the Troggs and the Seeds used four-on-the-floor on some of their hits.