There are three! A&J shows this weekend starting tomorrow (Friday) at 10am. There's also advice and a download of a "Bronhom" mask for actual Glasto Squadron people over at the A&J blog.
http://www.bbc.co.uk/blogs/adamandjoe/2 ... -get.shtml
Wear it and then "Meet near the left of the Pyramid Stage on Saturday between 10-10.30pm" and presumably await further instructions.