Star gives Austin Christy signed instrument


John Mayer surprised a fan at a gig by inviting him on stage to perform.

The singer noticed Austin Christy, 11, holding up a sign that read: ‘Can I play Belief with you?’

So John, 32, gave him a guitar and they jammed in front of the 25,000-strong crowd in Philadelphia. 

He even signed the instrument and gave it to Austin as a parting gift. 

SEE VIDEO John Mayer plays guitar with fan on stage…