The plan was simple: Justin Bieber would play two acoustic songs in the middle of his set, then hand off his guitar and get back to the programmed dance music.
But when a stagehand approached the young pop singer following a rendition of his song “Love Yourself,” Bieber casually waved him off. Clearly reluctant to give up the instrument, he instead launched into Tracy Chapman’s “Fast Car,” of all things, murmuring breathily as he plucked out the folk tune’s distinctive riff.
The thumping club beats would have to wait.
Bieber’s unexpected coffee-shop moment was one of many instances of old-fashioned musicianship at Jingle Ball,...