Does the The 3rd U.S. Infantry, traditionally known as "The Old Guard?

Question

perform plays?

Answer 1

NO they don't do plays.

The "Old Guard," one of the oldest and most respected Infantry Regiments in the United States Army, has the awesome responsibility of both guarding the Tomb of the Unknowns at Arlington National Cemetery, but also for escorting deceased Army servicemembers to their final rest in the "Gardens of Stone," as Arlington is sometimes called.

The "Old Guard" also serves as the Army's ceremonial unit
and, as an active and well-trained Infantry Regiment,
is responsible for the protection of Washington, D.C.

Here is some more info on what they do:
http://www.arlingtoncemetery.net/thirdinf.htm
http://www.army.mil/oldguard/index2.htm
http://www.tombguard.org/

Answer 2

No, they perform at ceremonies and parades, among a lot of other different duties, but no plays,
When I was stationed there years ago, in the 80's, they made a movie there and used many Old Guard Soldiers as extras, it was called Garden Of Stone, great movie