Obama appeared in a video, urging the crowd of nearly 50,000 to vote. West joined Jay-Z at the end of his set, performing hits like “Mercy” and “…In Paris” on Saturday night.

Before taking the stage, Jay-Z made his way down the steps of the Philadelphia Museum of Art — made famous by Rocky — as his song “Made In America” played in the background.

Jay-Z headlined the first night of the two-day festival he curated, performing hits like “Empire State of Mind” and “Big Pimpin’” in a 90-minute show.

Skrillex, Miike Snow and Janelle Monae also performed. Pearl Jam, Run DMC and Drake will perform Sunday.