Excellent recommendation letters take time to write.  Please be aware that a faculty member has responsibilities to each of their students as well as preparation for classroom teaching, ensemble score study, professional careers, etc., and a personal life.  If you need a recommendation letter, it is in your best interest to ask the faculty member as soon as possible.  Remember the saying, “Lack of planning on your part does not constitute an emergency on my part.” Be sure to give your instructor all information needed in regard to your letter including an addressed envelope with a stamp.