Podcast:Switched on Pop Published On: Thu Feb 18 2016 Description: What do Usher, The Band Perry and Bieber have in common? They all sing with Mama Jan, one of the best vocal coaches and producers in the music business. On this mini episode, Mama Jan talks about what happens backstage before the biggest performance of a lifetime. Learn more about your ad choices. Visit podcastchoices.com/adchoices