How to Quiet the Singing Toddler

We have finally discovered the secret to keeping this mischievous tyke quiet in church. Have someone else hold him. Twice now he has been held in church by someone other than Mom and Dad. Both times he has fallen blissfully asleep and slept all the way through Mass. Now to find a way to pack a third adult into the diaper bag to pull out during Mass when he starts to "sing" for us.