Backing p. pr. & vb. n. : of Back

Backing n. : The act of moving backward, or of putting or moving anything backward.

Backing n. : That which is behind, and forms the back of, anything, usually giving strength or stability.

Backing n. : Support or aid given to a person or cause.

Backing n. : The preparation of the back of a book with glue, etc., before putting on the cover.

Example:
What is the proper procedure for Backing out of a parking spot?

Taxonomy
backing vocals, backup singers, backing vocalist, songs, backup vocals, vocalists, lead vocalist, free encyclopedia, vocal harmonies, backing singer, sings, backup singer, backing vocalists, onstage, Band members, Lead singers, record songs, choruses.

Defination from the web:
backing vocals, because the sound of their own harmonies will blend well with their main vocal. Ian Gillan of Deep Purple and Brad Delp of Boston recorded lead and backing vocals for their albums. ...