Tenor Joseph Calleja has commanded the stage all over the world and entertained tens of thousands of people.
He has even serenaded a cow.
Now he's singing under water.
He offered an explanation on Facebook: "Just a few days left before my role debut as Rodolfo in Verdi's LuisaMiller at the Staatsoper Hamburg. I did study the role quite intensively going to a lot of effort to memorize it well and took the score everywhere, literally... Here is the proof."