Michael Clifford - 5 Seconds of Summer perform at the Perfect Vodka Amphitheatre at Perfect Vodka Amphitheatre - West Palm Beach, Florida, United States - Monday 14th September 2015 (1 Picture)
Photo credit: Johnny Louis
View All: 5 Seconds of Summer in concert
The acclaimed performer had just cancelled touring due to a battle with cancer.
Many ticket-holders couldn't get into the O2 Arena show on Tuesday night (September 19th) because they didn't bring photo ID to match their booking.