Summer Sonic, one of Japan’s two leading international summer music festivals, celebrated its landmark 20th anniversary in the same way it heralded its 10th, by adding a third day to its usual two-day lineup.

The fest is held simultaneously near Tokyo and in Osaka, the former at Zozo Marine Stadium and Makuhari Messe, and the latter at Osaka Maishima Sonic Park. This year the proceedings took place on August 16-18 and the lineup was studded with major headliners and popular acts from the Red Hot Chili Peppers, the Chainsmokers to Weezer, Baby Metal, Disclosure and K-pop act Blackpink. All three days of Tokyo tickets sold out by early July, and Osaka was largely sold out as well.

Promoter Creativeman reported attendance was 350,000 for the three days across both venues, making it the biggest summer music festival in Japan this year. That title usually goes to the Rock in Japan fest, which features exclusively domestic repertoire and regularly hosts 300,000. In addition, Summer Sonic was livestreamed on YouTube for the first time ever.