Hadley liked music (who didn't?) but he'd never had any interest in learning it himself. That is, until his pool of potential hobbies became a lot more limited to things he could do through touch and sound alone. Which coincidentally included music, something he now had someone who could teach him how to do.
One day he'd asked Jack to teach him how to play an instrument on a whim. They settled on the piano, since there happened to be an unused one sitting uselessly in the ballroom of the Earalas estate, where Hadley hosted events when he needed/wanted to interact with other important clio.
"Let's take a break," he said, after one particular practice session. "You thirsty? I'm thirsty. Want a drink?"