Composition (music) in the context of "Lead sheet"

In music, an arrangement is a musical adaptation of an existing composition. Differences from the original composition may include reharmonization, melodic paraphrasing, orchestration, or formal development. Arranging differs from orchestration in that the latter process is limited to the assignment of notes to instruments for performance by an orchestra, concert band, or other musical ensemble. Arranging "involves adding compositional techniques, such as new thematic material for introductions, transitions, or modulations, and endings. Arranging is the art of giving an existing melody musical variety". In jazz, a memorized (unwritten) arrangement of a new or pre-existing composition is known as a head arrangement.

In Western musical theory, a cadence (from Latin cadentia 'a falling') is the end of a phrase in which the melody or harmony creates a sense of full or partial resolution, especially in music of the 16th century onwards. A harmonic cadence is a progression of two or more chords that concludes a phrase, section, or piece of music. A rhythmic cadence is a characteristic rhythmic pattern that indicates the end of a phrase. A cadence can be labeled "weak" or "strong" depending on the impression of finality it gives.

While cadences are usually classified by specific chord or melodic progressions, the use of such progressions does not necessarily constitute a cadence—there must be a sense of closure, as at the end of a phrase. Harmonic rhythm plays an important part in determining where a cadence occurs. The word "cadence" sometimes slightly shifts its meaning depending on the context; for example, it can be used to refer to the last few notes of a particular phrase, or to just the final chord of that phrase, or to types of chord progressions that are suitable for phrase endings in general.

Progressive rock (shortened to prog rock or simply prog) is a broad genre of rock music that primarily developed in the United Kingdom through the mid- to late 1960s, peaking in the early to mid-1970s. Initially termed "progressive pop", the style emerged from psychedelic bands who abandoned standard pop or rock traditions in favour of instrumental and compositional techniques more commonly associated with jazz, folk, or classical music, while retaining the instrumentation typical of rock music. Additional elements contributed to its "progressive" label: lyrics were more poetic, technology was harnessed for new sounds, music approached the condition of "art", and the studio, rather than the stage, became the focus of musical activity, which often involved creating music for listening rather than dancing.

Progressive rock includes a fusion of styles, approaches and genres, and tends to be diverse and eclectic. Progressive rock is often associated with long solos, extended pieces, fantastic lyrics, grandiose stage sets and costumes, and an obsessive dedication to technical skill. While the genre is often cited for its merging of high culture and low culture, few artists incorporated classical themes in their work to a significant degree, and only a handful of groups, such as Emerson, Lake & Palmer and Renaissance, intentionally emulated or referenced classical music.

In music, a cantus firmus ("fixed melody") is a pre-existing melody forming the basis of a polyphonic composition.

The plural of this Latin term is cantus firmi, although the corrupt form canti firmi (resulting from the grammatically incorrect treatment of cantus as a second- rather than a fourth-declension noun) can also be found. The Italian is often used instead: canto fermo (and the plural in Italian is canti fermi).