Counter-melody in the context of Counterpoint

A part in music refers to a component of a musical composition. Because there are multiple ways to separate these components, there are several contradictory senses in which the word "part" is used:

• any individual melody (or voice), whether vocal or instrumental, that can be abstracted as continuous and independent from other notes being performed simultaneously in polyphony. Within the music played by a single pianist, one can often identify outer parts (the top and bottom parts) or an inner part (those in between). On the other hand, within a choir, "outer parts" and "inner parts" would refer to music performed by different singers. (See § Polyphony and part-writing)
• the musical instructions for any individual instrument or voice (often given as a handwritten, printed, or digitized document) of sheet music (as opposed to the full score which shows all parts of the ensemble in the same document). A musician's part usually does not contain instructions for the other players in the ensemble, only instructions for that individual.
• the music played by any group of musicians who all perform together for a given piece; in a symphony orchestra, a dozen or more cello players may all play "the same part" even if they each have their own physical copy of the music. This part may be in unison or may be harmonized, and may even sometimes contain counter-melodies within it. A percussion part may sometimes only contain rhythm. This sense of "part" does not require a written copy of the music; a bass player in a rock band "plays the bass part" even if there is no written version of the song.
• a section in the large-scale form of a piece. (See § Musical form)

A backing vocalist is a singer who provides vocal harmony with the lead vocalist or other backing vocalists. A backing vocalist may also sing alone as a lead-in to the main vocalist's entry or to sing a counter-melody. Backing vocalists are used in a broad range of popular music, traditional music, and world music styles.

Solo artists may employ professional backing vocalists in studio recording sessions as well as during concerts. In many rock and metal bands (e.g., the power trio), the musicians doing backing vocals also play instruments, such as guitar, electric bass or keyboards. In Latin or Afro-Cuban groups, backing singers may play percussion instruments or shakers while singing. In some pop and hip-hop groups and in musical theater, they may be required to perform dance routines while singing through headset microphones.