Introduction (music) in the context of "Arranger"

An instrumental, instrumental music, or sometimes "instrumental song" is music without any vocals, although it might include some inarticulate vocals, such as shouted backup vocals in a big band setting. Through semantic widening, a broader sense of the word "song" may refer to instrumentals. The music is primarily or exclusively produced using musical instruments. An instrumental can exist in music notation, after it is written by a composer; in the mind of the composer (especially in cases where the composer themselves will perform the piece, as in the case of a blues solo guitarist or a folk music fiddle player); as a piece that is performed live by a single instrumentalist or a musical ensemble, which could range in components from a duo or trio to a large big band, concert band or orchestra.

In a song that is otherwise sung, a section that is not sung but which is played by instruments can be called an instrumental interlude, or, if it occurs at the beginning of the song, before the singer starts to sing, an instrumental introduction. If the instrumental section highlights the skill, musicality, and often the virtuosity of a particular performer (or group of performers), the section may be called a "solo" (e.g., the guitar solo that is a key section of heavy metal music and hard rock songs). If the instruments are percussion instruments, the interlude can be called a percussion interlude or "percussion break". These interludes are a form of break in the song.

Song structure is the arrangement of a song, and is a part of the songwriting process. It is typically sectional, which uses repeating forms in songs. Common piece-level musical forms for vocal music include bar form, 32-bar form, verse–chorus form, ternary form, strophic form, and the 12-bar blues. Popular music songs traditionally use the same music for each verse or stanza of lyrics (as opposed to songs that are "through-composed"—an approach used in classical music art songs). Pop and traditional forms can be used even with songs that have structural differences in melodies. The most common format in modern popular music is introduction (intro), verse, pre-chorus, chorus, verse, pre-chorus, chorus, bridge, and chorus, with an optional outro. In rock music styles, notably heavy metal music, there are usually one or more guitar solos in the song, often found after the middle chorus part. In pop music, there may be a guitar solo, or a solo performed with another instrument such as a synthesizer or a saxophone.

The foundation of popular music is the "verse" and "chorus" structure. Some writers use a simple "verse, hook, verse, hook, bridge, hook" method. Pop and rock songs nearly always have both a verse and a chorus. The primary difference between the two is that when the music of the verse returns, it is almost always given a new set of lyrics, whereas the chorus usually retains the same set of lyrics every time its music appears." Both are essential elements, with the verse usually played first (exceptions include "She Loves You" by The Beatles, an early example in the rock music genre). Each verse usually employs the same melody (possibly with some slight modifications), while the lyrics usually change for each verse. The chorus (or "refrain") usually consists of a melodic and lyrical phrase that repeats. Pop songs may have an introduction and coda ("tag"), but these elements are not essential to the identity of most songs. Pop songs often connect the verse and chorus via a pre-chorus, with a bridge section usually appearing after the second chorus.

In music, a section is a complete, but not independent, musical idea. Types of sections include the introduction or intro, exposition, development, recapitulation, verse, chorus or refrain, conclusion, coda or outro, fadeout, bridge or interlude. In sectional forms such as binary, the larger unit (form) is built from various smaller clear-cut units (sections) in combination, analogous to stanzas in poetry or somewhat like stacking Lego.

Some well known songs consist of only one or two sections, for example "Jingle Bells" commonly contains verses ("Dashing through the snow...") and choruses ("Oh, jingle bells..."). It may contain "auxiliary members" such as an introduction and/or outro, especially when accompanied by instruments (the piano starts and then: "Dashing...").