Amid all of the sounds emanating from Grant Park during Lollapalooza weekend, you can also add "ka-ching."
The music festival draws hundreds of thousands of people every year, which translates to an estimated $85 million of revenue for the city -- 85 percent of it from tourists.
"If the hotels are busy, the restaurants are busy, our retail partners are busy, so there adds a vibrancy downtown that's just fantastic," says Don Welsh of Choose Chicago.
Over the past nine years in Chicago, Lollapalooza has grown into one of the largest music festivals in the world.
For Michigan Avenue restaurant The Gage, that translates into of their busiest weekends of hte year.
"Things usually get going the Wednesday before the event and goes through the Tuesday after. There's a lot of tourist in town and it's usually one of our busiest weekends of the year," owner Billy Walsh says. "(It's) a more mature affluent crowd who really enjoys music, and a lot of them are our regulars."
It's the same story further up Michigan Avenue at the Intercontinental Hotel.
"Big weekend. Every year they sell us out at the hotel, and our location here on Michigan Avenue is a big draw," GM Don Egan says.