The Smashing Pumpkins brought out Barry Williams — the actor who played Greg Brady on The Brady Bunch — to perform 'It's a Sunshine Day' at a Lollapalooza aftershow at Chicago's Riviera Theatre. Williams, backed by a quartet of background singers, joined the band for the 1972 song written by Steve McCarthy and made famous by the Brady Bunch cast. Rolling Stone

The crossover didn't come out of nowhere. Billy Corgan hosts a podcast called 'The Magnificent Others,' and in May — roughly two months before the Riviera show — he interviewed Williams for an 80-minute conversation recorded at the Brady Bunch house. That meeting appears to have laid the groundwork for the stage collaboration.

Williams wasn't the only guest at the Riviera. Melissa Auf der Maur, former bassist for Hole and a onetime Smashing Pumpkins touring member, also joined the band during the same concert to perform 'The Everlasting Gaze,' a track from the Pumpkins' 2000 album Machina/The Machines of God. Rolling Stone's report includes embedded video footage of both the 'It's a Sunshine Day' performance and the Auf der Maur appearance.

The aftershow setlist centred on Mellon Collie and the Infinite Sadness, the band's 1995 double album, giving the Chicago crowd a deep run through one of the Pumpkins' most commercially successful records. The aftershow was a warm-up of sorts: the Smashing Pumpkins were scheduled to perform at Lollapalooza proper the following Friday.

For a band whose frontman has spent three decades threading pop culture into alternative rock, the Greg Brady moment landed somewhere between sincere and surreal — a sitcom cast member singing a fifty-four-year-old television song inside a theatre built for rock shows, with one of the nineties' defining bands backing him. The embedded footage circulating from the night suggests the audience took it in that spirit.