 On August 6, Stirling came back after four years to "America's Got Talent" to perform as host, along with Lzzy Hale their single "Shatter Me".In August, it was revealed that Stirling would be part of two collaborations.The first one was revealed on August 13, and was about Stirling collaborating for a second time with the "a cappella" group Pentatonix for their third studio album "PTX, Vol.