Red, White and Blue

Tonight fellow Blipper W and I went to see Michael Ball at the Hammersmith Apollo. He was supported by Amy Wadge, also a great singer/songwriter. Michael was excellent, as were his band and backing singers. 
We were also treated to a surprise appearance from Alfie Boe!
It was a great night.
Can you guess from which musical Michael was singing songs at the time of my Blip?