Opening act

An opening act, also known as a warm-up act, support act, supporting act or opener, is an entertainment act (musical, comedic, or otherwise), that performs at a concert before the featured act, or "headliner". Rarely, an opening act may perform again at the end of the event, or perform with the featured act after both have had a set to themselves.

The opening act's performance serves to "warm up" the audience, making it appropriately excited and enthusiastic for the headliner.