There really is a really rather excellent all-dayer at The Windmill (that's in London) on Aug 10th. FREE BBQ. And there are bands.
It's brought to you by Cool For Cats. Line-up:
OFFICIAL SECRETS ACT
KEITH TOTP (AND HIS MINOR UK INDIE CELEBRITY ALLSTAR BACKING BAND)
It is 6 quid and starts at 4.30pm.