at the drop of a hat

At once, without delay. It is thought to come from the practice of dropping or waving a hat as a starting signal for a race, fight, or other event. The phrase also has come to mean “without further encour- agement.” The British composers Michael Flanders and Donald Swann, known for their humorous songs and revues, told their friends they could be per- suaded to sing their songs “at the drop of a hat,” which in the mid 1950s became the title of their first record album, followed by At the Drop of Another Hat. The term has been a cliché since the mid-1900s.