Justin Timberlake accomplished a rare feat: He made the leap from teen idol to serious pop artist. In doing so, the former *NSYNC member paved the way for other pop stars to grow up in public, whether they were breaking free of boy bands—like former One Direction member Liam Payne and ex-Disney Channel staple Nick Jonas—or starting their solo careers early, in the manner of American Teen Khalid and onetime child star Drake.