The testimony of a subscribing witness is not necessary to authenticate a writing unless required by statute.
Tenn. R. Evid. 903
Advisory Commission Comments.
In will contests, T.C.A. § 32-4-105 requires calling subscribing witnesses to a will.
Advisory Commission Comment [2010].
The title of the rule is changed to reflect reality. A Tennessee statute does not necessitate testimony of all living witnesses in a will contest "if to be found." T.C.A. § 32-4-105.