Elvis Presley’s comeback engagement in Las Vegas, in August 1969, was a spectacular success, drawing rave reviews and more people than any other show in Las Vegas history. The show not only revitalized Elvis’s career; it changed the face of Vegas entertainment for good.

Elvis’s show was something new; not an intimate, Sinatra-style night-club show, but an over-the-top, rock-concert-style extravaganza in the city’s largest showroom. Elvis set a new bar for Vegas performers; the biggest salary, the biggest musical production, and the biggest promotion campaign the city had ever seen. What’s more, he brought a new mass audience to Vegas from Middle America that Vegas depends on for its success to this day.

Richard Zoglin is also the author of Hope: Entertainer of the Century and Comedy at the Edge: How Stand-up in the 1970s Changed America. He is a contributing editor for TIME magazine, where he has spent more than 30 years as an editor, writer and most recently as the magazine’s theater critic.