The I Want It That Way singer's 13-year-old is following will be stepping into the spotlight when the production opens at the Nederlander Theatre in February (16).
Baylee will play twins in the musical, which is set on a floating casino plagued with earthquakes, infernos and tidal waves, and features pop, rock and disco hits from the 1970s.
Brian took to Instagram.com on Thursday (07Jan16) to share his pride and joy over his son's first big break, writing, "a BACKSTREETS's BOY on Broadway.... #proudpappa (sic)."
Disaster! also features Broadway veterans Adam Pascal, Kerry Butler, Faith Prince and Tony Award winner Roger Bart.