My grandmother (who was born in 1896) used to talk about Irish tenors sometimes, both to quote a line from a poem that she loved that went "They shot a man like Lincoln and let that tenor live" and also to sing some of her favorites. "I'll Take You Home Again, Kathleen" was a standard part of the repertoire of any vaudevillian tenor -- and from what she said, they were always billed as "Irish" no matter where they came from. But tenor voices were very popular in music halls in the days before electrical amplification. Like sopranos, they could be heard more clearly to the back of the hall, and were well-suited to the florid popular style of the day.