We've seen festival appearances boost sales in the past, but rarely as dramatically as this.
Last week, Lionel Richie had - it seemed - most of Glastonbury dancing on the ceiling during his Sunday afternoon 'Legends' spot. Now, he's dancing on the top of the charts, having scored his first No 1 album in the UK for 23 years.
Lionel Richie & The Commodores: The Definitive Collection peaked at No. 10 when it was released in 2003, but now it's at the summit, holding off another who impressed at Glasto, Florence + The Machine.
It's the last album which will have the honour of being unveiled as a chart-topper on a Sunday - as global releases synchronise to Fridays (where they've always been here, trend-setters that we are) the chart will be revealed before the weekend from next week forth.