Lady Gaga reportedly played to 2.5 million fans during her concert at Copacabana Beach in Rio de Janeiro, Brazil, on Saturday night. It’s a hard-to-fathom crowd size, considering we’ve never seen anything like it for a concert in the United States.

When it comes to free U.S. shows, some estimates put Garth Brooks’ 1997 concert in New York’s Central Park — nicknamed “Garthstock” — around 900,000 or even 1 million fans. (For non-concert crowds, the Chicago Cubs’ 2016 World Series celebration reportedly drew 5 million fans for a parade and rally — but that’s not a single-stage event.)

On the new Billboard Pop Shop Podcast, Katie & Keith are talking about the positively massive show and whether it could ever be replicated here in the U.S. — like, are Los Angeles beaches even big enough for such a thing? And where would people park?!?

Also on the show, we’ve got chart news on how Ghost scores its first No. 1 on the Billboard 200 albums chart — and brings hard rock back to No. 1 for the first time in four years. Plus, how Alex Warren’s “Ordinary” hits a new high on the Billboard Hot 100, climbing all the way to No. 2.

The Billboard Pop Shop Podcast is your one-stop shop for all things pop on Billboard‘s weekly charts. You can always count on a lively discussion about the latest pop news, fun chart stats and stories, new music, and guest interviews with music stars and folks from the world of pop. Casual pop fans and chart junkies can hear Billboard‘s executive digital director, West Coast, Katie Atkinson and Billboard’s managing director, charts and data operations, Keith Caulfield every week on the podcast, which can be streamed on Billboard.com or downloaded in Apple Podcasts or your favorite podcast provider. (Click here to listen to the previous edition of the show on Billboard.com.)