If you are fiddling through a music book when you should be playing, you probably dont have?\nOptions:\n- practice\n- dexterity\n- idle time\n- knowledge of music\n- conductor Let's think step by step:
User
When person don't have knowledge of music, he just fiddle the music book instead of playing music from it. To read the notation of music theory book person must have knowledge of music. So, the answer is knowledge of music.
Assistant