His Broadway debut was as a "swing" in the musical
Side Show in 1997. He appeared in the musical
Weird Romance in April 2004 at the
York Theatre, New York, and the musical
God Bless You, Mr. Rosewater in April 2005 at the York Theatre. He went on to star as "Nick Massi" in the original Broadway cast of the musical
Jersey Boys (2005). He starred in the Broadway musical
Next to Normal, for which he received a
Tony Award nomination as
Best Actor in a Musical. He was also in the
Arena Stage production (2008) and received a
Helen Hayes Award nomination for Outstanding Lead Actor in a Non-Resident Production. He departed from the production on May 16, 2010, and was succeeded by original Off-Broadway cast member
Brian d'Arcy James. Spencer starred as
Abraham Lincoln in the 2014
New York Musical Theatre Festival production of
Bayonets of Angst, a bluegrass musical comedy about the Civil War. Spencer was awarded a New York Musical Theatre Festival Award for Excellence for "Outstanding Individual Performance." He also has formed his own company, "7 Spencer Productions", for which he produces, writes, directs and acts in his own low-budget movies. As a voice actor, Spencer was the voice of Seita in the anime movie,
Grave of the Fireflies. For television he has appeared on
Law & Order,
All My Children, and
Girls Behaving Badly. == Personal life ==