Reading closed its Warehouse stage on Friday around a Skepta B2B Prospa booking, the set cancelled after the crowd overflowed. The same weekend at Electric Picnic, Armand Van Helden lost his 90 minutes on the Smirnoff stage, stopped over crowd safety. Two countries, two bills, one shape: more people turned up than the room could take.

Festival Republic's Melvin Benn put it on the record. Van Helden had been booked onto a stage he was too big for, Benn told The Irish Times, and organisers pulled the set rather than risk injuries or lives. He was less generous about the crowd-safety criticism that followed. Stopping it was the right call, and it only became necessary because a headline draw was programmed into a tent.

Neither act was a surprise package. Van Helden and Prospa are close enough to share a record: Prospa's remix of I Want Your Soul has both names on it.

Prospa made the obvious argument afterwards, that dance acts drawing this kind of crowd need bigger tents or a main-stage slot. Leeds closed its own Warehouse stage more than once across the same weekend. The Guardian's Reading and Leeds review got there from the other side, finding the Warehouse was where the weekend's real energy sat.

The booking has moved and the site plan has not. Dance programming still gets treated as the alternative option, a second-tier tent for people who want something other than whoever is closing the main stage. Except that crowd is now the crowd. It arrives early and it stays.

Festivals can plan for this when they decide to. Overdose training got written into the show build at Insomniac and Goldenvoice sites because someone pushed it upstream into production instead of leaving it at the medical tent. Tent capacity is a smaller problem than that one, and it is sitting on a lineup poster months before anybody queues.