The website only displays artistes which are booked for the Ham concerts. The rest of the week ( including Anahata and myself, plus Nick & Mary Barber's Big Band Workshop) are not displayed. As Kitty says, you need to look at the newsletter which gives some hints about who is going to be there. The list of artistes is on the front page of the newsletter and is not exhaustive.
There will be plenty of people there, I can assure you, though not all performing in the evening concerts at the Ham! And some of the Ham performers will be elsewhere during the festival.