Hampshire and Isle of Wight Air Ambulance says 10,000 missions is a major milestone. It's saved thousands of lives since it was launched in 2007.
Liam Gallagher will be top of the bill on Friday while Snow Patol, David Guetta and Duran Duran will headline the weekend.
The 80 year old Class 483s have served the Isle of Wight since 1990. The line will be closed for an upgrade for three months with a bus replacement service.