“Today, I am a singer,” Alec Su You-peng says shortly after he sits down. After nearly three decades, Su, formerly a member of one of the earliest Chinese boy bands, is ready to make a comeback as a singer in another band this year with new music. Such is its power — music always has a way of making enthusiasts return to it no matter how long they have been away. Music is as vital as water Su learned to play the keyboard at a very young age. However, when he was in middle school, his parents wanted him to...