Bumper music, or a bump, is a term used in the radio broadcasting industry to refer to short clips of signature or theme music used to buffer transitions between programming elements. It is also a term for music played at music venues such as concerts before show time, to "fill the air", with a musical atmosphere. Bumper music is commonly employed when a syndicated program takes a break for local station identification or "goes to a radio commercial." More often than not it is called a "bump" in today's radio; NPR also uses the term "button". It is also referred to as "rejoiner music" when the bumper music marks the end of a local break on a radio network.