The simplest PA system consists of a microphone, an amplifier and one or more speakers. Whenever you have those three components, you have the potential for feedback. Feedback happens when the sound from the speakers makes it back into the microphone and is re-amplified and sent through the speakers again, like this:
Home SparkNotes â History Study Guides â The Great Depression (1920â1940) â The Roaring Twenties and the Jazz Age: 1920â1929.
The roaring twenties ushered in a rich period of American writing, distinguished by the works of such authors as Sinclair Lewis, Willa Cather, William Faulkner, F. Scott Fitzgerald, Carl Sandburg and Ernest Hemingway. A uniquely American music form, whose roots lay in African expression, came to be known as jazz.