Answer to Question 1
A life story is an accurate (tape recorded) autobiography of a consultant's life told in his/her own words without interruptions or questions by the interviewer.
A life history is the consultant's life story resulting from direct and frequent questioning by the interviewera collaborative biography rather than an autobiography.
Answer to Question 2
Be careful to ensure that the consultant is discussing his/her world of music in his/her own words. Other problems can be the beginning fieldworker's concern over the tape recorder and his/her asking leading questions (questions that lead the consultant to a particular answer).