Can you see them?

Today, I was helping out at the Aden Music Festival in Mintlaw.
Nothing too demanding, just keeping an eye on the disability area.
This group was called The Invisibles. Even their instruments were invisible, apart from the drums.
They were rather good, especially their version of this https://youtu.be/gH6i9JAdJrQ?si=wkUoNNVZy5BkQv8J