ah ah very strange indeed
here are some precisions form my colleague :
An artist played at least 30 mn on a keyboard and a computer on the right half of the stage. He played on some Beatles songs, adding sounds and noises… a kind of DJ-electro performance. It did not appear as a first part because there was no light and no announcement. But It actually was it. Even if most of the people did not even noticed, and even if it wasn't mentionned on the ticket. Someone in the crowd said "come, there is a first part" maybe because he heard of this, or because he saw other gigs of the same tour before ?