I am pretty much an uncle to the current teenage generation of Muslims. All I know is that Justin Bieber and One Direction are the Justin Timberlake and Backstreet Boys, respectively, of their generation. I am all for better alternative musical talents for Muslims to consume. My recommendation would be not to go down the nasheed route like Maher Zain or Sami Yusuf. That limits your audience to Muslims. They should go the Lupe Fiasco or Yuna route, whom both are Muslims but internationally acclaimed artists. Whichever fiqh opinion they choose for their music they should spread the message to a wider audience. May Allah continue to bless them and guide them. Ameen!