An 'Indulgence' of dulcimers ?
I call them "the big one, and the little one." But daughter Marianne calls the big one "Chupacabra." Those with a large herd might need a term for the group, but I guess a single word could stand for a variable number. 30 cattle are a herd, 100 cattle are still a herd. 12 would be a dozen, 13 a luthiers dozen. 20 would be a score. Four Score would probably upset Mrs. Wanda, but two seems to be OK with her.