As expected, Paul McCartney was the star act as Apple concluded its 50th anniversary celebrations at Apple Park, and employees have been sharing videos of the party.Apple Park celebrations — image credit: Steven PetersonMcCartney's appearance had been rumored in the past few days and then confirmed as images from his soundcheck at Apple Park were shown across social media. Now he's played a career-spanning set in front of thousands of Apple employees, many of whom have been sharing images and vi...