How did the centre of the song publishing industry become known as “Tin Pan Alley”?

Tin Pan Alley is an actual place in New York City. It’s the nickname for the side streets off Times Square, where for generations music publishers have auditioned new songs. The name came from the late 1800s, when the awful sound of cheap tinny pianos coming through the open office windows of hundreds of publishers was likened to the beating of tin pans.