Justin Bieber finds redemption in ‘Purpose’ tour

On his Purpose world tour, which arrived at the SAP Center in San Jose on Thursday night, the fallen pop idol serenaded them with an acoustic guitar, dazzled them with elaborate dance routines, showed off his drumming skills, did backflips on a trampoline suspended over their heads and fell on bended knee to hold their hands and whisper sweet nothings in their ears. Oh, and in case that didn’t do the trick, Bieber closed the 90-minute set by ripping off his shirt and walking through a waterfall — yes, right there onstage — as he grabbed his crotch and mouthed the words to his irresistible tropical house hit, “Sorry.” In the past year, Bieber’s hard driving comeback effort has resulted in his first Grammy win and a new album, “Purpose,” that has already spawned three No. 1 singles. The setlist, meanwhile, running the gamut from his teen-pop hits from 2010 like “Baby” and “Boyfriend” through the as-yet-unreleased “Insecurities,” played acoustically on a couch alongside “Love Yourself” and “Home to Mama,” reinforced his standing as a pop wunderkind who’s not going anywhere anytime soon. Aidin Vaziri is the San Francisco Chronicle’s pop music critic.