Once we saw two guitarist on the stage, from different countries, the one from US, will rock his body back and forth while playing, with some head twisting, and standing on toes and stuffs. The other Asian guitarist, just looked at the fretboard, and play. My friend told me, see, the asian guitarist is not as good as the US one, he is just practicing, not really playing from his heart! Do you judge people playing from just looking at they way they play? Would you have prejudice if they just stood there and play? I know most Saxophonist have very little movements during performance compared to guitarist and bassist and drummer.