The morning chat show, hosted by Kelly Ripa, airs in the New York metropolitan area on ABC 7 beginning at 9 AM ET; check local listings.
The June 6 program will also feature Julianne Hough; the June 7 broadcast will include Jessica Chastain and Emili Sande.
Harris has been seen on Broadway in Assassins, Proof and Cabaret. He also starred in the New York Philharmonic production of Company. The performer is the winner of two 2010 Emmy Awards and was nominated for his work on the CBS series "How I Met Your Mother."