Although he is known for his television roles and he continues to be seen frequently in guest-starring roles on television today, Garrison is primarily a theatre actor, particularly in musicals. He has appeared in numerous productions around the United States, including many Broadway shows. His Broadway appearances include A Day in Hollywood / A Night in the Ukraine for which he received a Tony Award nomination, Wicked, The Visit, Titanic, Torch Song Trilogy, The Pirates of Penzance, Bells Are Ringing, A History of the American Film, and Off-Broadway in I Do! I Do!, for which he received a Drama Desk Award nomination, Dead Poets Society, Middletown, New Jerusalem, Geniuses, It’s Only a Play, By the Way Meet Vera Stark, and Silence! The Musical. In addition to the cast albums of Hollywood/Ukraine, Titanic, Bells Are Ringing, The Visit, I Do! I Do!, and On the Town, his many recordings include Songs of New York, Show Boat, Kiss Me Kate, Annie Get Your Gun, Of Thee I Sing/Let ’Em Eat Cake, Girl Crazy, You Never Know, Tell Me More, Oh! Lady! Lady!!, George and Ira Standards and Gems, and, as a guest Artist, Dawn Upshaw Sings Rodgers and Hart.”.