1. Do his friend-musicians have to take part-time day job? (общий тип)
2. Why do some of his friends-musicians have to take part-time day job? (специальный тип)
3. Do some of his friends-musicians or some of his classmates have to take part-time day job? (альтернативный тип)
4. Who has to take part-time day job? (вопрос к подлежащему)