in the style picker you get the chance to try the style. look at the bottom of the stylepicker and you can either play using the chords of your song or the premade demo.

when the stylepicker is open set your options - time signature, tempo and genre and then when you get a list of styles highlight the one you want to audition. if you don't like it, stop it and highlight another. don't press ok until you want to change to the style you've chosen