Today, October 6th is the day in 1927 that “The Jazz Singer” opened, with Al Jolson in the title role. The Jazz Singer wasn’t the first film with sound, but it was the first full-length film with synchronized dialogue, even if only a few minutes. But it changed not just Hollywood, but the whole entertainment business: as the actor leading in a stage production of The Jazz Singer said:

“A week or two after the Washington engagement the sound-and-picture version of The Jazz Singer with Al Jolson was sweeping the country, and I was swept out of business. I couldn’t compete with a picture theatre across the street showing the first great sound picture in the world…for fifty cents, while the price at my theatre was $3.00.”

That quote is from the Wikipedia article, which is pretty comprehensive in its detail and fully referenced.