The sold out three-day BottleRock Napa Valley Festival got underway on Friday, with Stevie Wonder and Lenny Kravitz set to perform.
Other headliners this weekend include Florence and the Machine and the Red Hot Chili Peppers.
There will also be food and wine demonstrations.
Even though festival tickets are sold out, you can still buy "aftershow" tickets with special performances.
The music festival started in 2013 and was a bit shaky, but it changed ownership and has now found a groove by signing a 10 year lease. Promoters expect 40,000 people a day, for the 78 musical acts. The concert sold out in April and prices for the three days ranged from $200 for three days to $3,000.
Bottlerock runs through Sunday.
Click here for the full lineup.