They were one of rock's most impressive live acts.
Idiom(s) section. act of God (law) an event caused by natural forces beyond human control, such as a storm, a flood or an EARTHQUAKE be/get in on the act (informal) to be/become involved in an activity that somebody else has started, especially to get something for yourself do, perform, stage a disappearing/vanishing act (informal) to go away or be impossible to find when people need or want you get your act together (informal) to organize yourself and your activities in a more effective way in order to achieve something: He needs to get his act together if he's going to pass. a hard/tough act to follow a person who is so good or successful at something that it will be difficult for anyone else coming after them to be as good or successful in the act (of doing something) while you are doing something: He was caught in the act of stealing a car. — more at CLEAN verb, READ verb