Led Zeppelin's O2 Arena reunion (2007)
Led Zeppelin reunited for a single concert at London's O2 Arena, billed as a tribute to founding manager Ahmet Ertegun. The roughly 20,000-seat show sold out within an hour of tickets going on sale.
Millions applied for tickets; the one-night show became a defining event in the band's legacy and produced the 'Celebration Day' film and album.
It set a benchmark for classic-rock reunion concerts: decades after a band's prime, nostalgia alone can fill a major arena in minutes.
Triumph's Grand Rapids date tests the same dynamic — whether a band long past its commercial peak can still draw a near-capacity arena crowd on name recognition alone.
