Brothers Gage consists of brothers Brody and Alex Gage. Brody is 15 and Alex is 17.
They both started playing harmonica when they were 5 years old. Within the next few years, they began singing, playing guitar, bass, drums, and keyboards. They've been performing shows since 2013. 
Brothers Gage's audition in Episode 1506 consisted of playing an original song called “Trading Eights” on the harmonica.  Howie Mandel, Eric Stonestreet, Sofia Vergara, and Simon Cowell all voted "Yes", sending them to the next round.
Brothers Gage's Judge Cuts performance in Episode 1508 consisted of performing a harmonica duet of LMFAO's "Party Rock Anthem". Their performance was not strong enough to advance to the Quarterfinals, eliminating them from the competition along with Craig Reid.