"Whether you consider it a new tradition or an ancient one, the latest to rise through those ranks is 23-year-old Julia Michaels, who had a No. 1 song as a co-writer with Justin Bieber's "Sorry" and has credits on recent albums by Selena Gomez, Britney Spears, and Gwen Stefani. Having had as much success as a gun-for-hire as she has doesn't necessarily augur for a distinctive voice. But "Nervous System," her debut EP, reveals Michaels as a gifted enough singer and confession-inclined enough songwriter that leaving out the middleman was definitely the way to go. Her track record isn't bad, but she's even more promising than her resume".