Claim: Battle Studies World Tour was the tour of a singer-songwriter whose birth year is 1977.
Evidence: Battle Studies World Tour was a worldwide tour by American singer John Mayer.
John Clayton Mayer -LRB- -LSB- ˈmeɪ.ɚ -RSB- born October 16 , 1977 -RRB- is an American singer-songwriter , guitarist , and producer.