Watch Justin Bieber Sing 'Baby' With a Young Fan in a Super Sweet Moment

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Justin Bieber
is continuing to make huge strides as he rehabilitates his image.

On Tuesday, the newly 21-year-old debuted a new look on Instagram – a spin on his old hairstyle that helped capture millions of Beliebers' hearts when he shot to superstardom in 2010.

“Hello old bieber hair I got it back lol,” the “Boyfriend” singer captioned the hair post.

And later that day, JB showed up to play ball at the 11th annual Desert Smash tennis tournament, hosted by Will Ferrell. The charity event raises money for Cancer for College, a non-profit organization that provides college scholarships to cancer survivors.

After playing a few matches, the Biebs took the stage for a private concert inside and performed a series of hits including for adoring onlookers including “Baby” and “Boyfriend.”

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At one point, the singer passed the mic to a young fan and let her belt out a few lines of “Baby” and then gave her a high-five. Watch the video above to see the sweet exchange.

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Next up, Justin is preparing for his big Comedy Central roast – set to tape this Saturday. From there, he’ll venture to Las Vegas for a huge birthday bash at Omnia nightclub.

In honor of Bieber’s birthday month, we've compiled our favorite one-on-one moments with the singer! Check out all the cuteness in the video below.

Chat all things Justin Bieber with @Katie_Krause on Twitter!