Watch Justin Bieber Cover Boyz II Men's 'I'll Make l’amour To You' 

Justin Bieber arrives at 102.7 KIIS FM\'s Wango Tango held at StubHub Center on May 9, 2015 in Los Angeles, California.  

After recently having "pretty much the best day" of his life, Justin Bieber popped into Jazz Night at the W Hotel in Hollywood to cover a classic R&B jam.

Is This Justin Bieber\'s \'Best Day of My Life\'? Pretty Much

The 21-year-old pop star made an impromptu appearance at the L.A. hotel on Sunday, May 24, and delivered a soulful performance of Boyz II Men\'s 1994 hit "I\'ll Make Love to You."

Bieber is currently working on new music and shooting the video for his Skrillex/Diplo collaboration "Where Are U Now."

Watch a clip of "I\'ll Make Love to You" performance below (via TMZ).

Ultimate Summer Festival Guide: Who to See, What to Wear, Where to Stay

Repeat Offenders: Musicians Playing More Than One Summer Festival in 2015

Ultra Crosses Over: 10 Highlights From a Star-Studded Weekend

Steve Angello on Dance Music: \'We Need to Be Able to Take It Seriously Again\'

Exclusive: Dillon Francis Premieres Rollicking New Remix of Zomboy\'s \'Nuclear\'

Electric Daisy Conflict: Inside the Bitter Legal Battle Between the EDM Biz\'s Biggest Rivals