The tenor will sing "O Holy Night" at the mass, which will be televised in New York City and around the country.
The 90-minute broadcast begins at midnight ET on December 25. It will be seen on WPIX-TV, channel 11, in New York. Check local listings for other outlets.
A onetime truck driver and part-time bounty hunter, Tanner has appeared at Santa Fe Opera, La Scala, Deutsch Opera Berlin, and the Metropolitan Opera. His roles include Calaf in Turandot and Don Jos_ in Carmen.