What if you don't like the styles on your arranger. You can with some effort make your own but since Yamaha for instance don't really encourage you to do that it gets difficult. So you use Band-in-a-Box or Jammer to generate a few extra styles. Is that cheating? I don't think so, especially not for the solo performer. As Uncle Dave says, we're making music and anything that adds to the performance is always welcome.