Jims2015, it sounds like we do it the same way.
Our Taurus has MyFord touch and the Lincoln has sync 3. With the Taurus, if you have been listening to FM or Sirius, after pressing the voice button, I think you say "USB." It will say "USB, please say a command." Then you can say what playlist you want, such as "Play playlist, best 90s pop." It will then play it in the order it was put on the flashdrive. With Sync 3, all I have to do is press the voice button and after it responds, say "play best 90s pop" and it will play it no matter what music source it was on before.