Alyson Renae Michalka (born March 25, 1989), often credited as Aly, is an American actress, singer-songwriter, guitarist, and pianist. She is perhaps best known for her role as Keely Teslow in the Disney Channel Original Series, Phil of the Future and as Taylor Callum in the Disney Channel Original Movie Cow Belles. She is also known as the one-half of the musical duo Aly & AJ with her sister Amanda Michalka..