Question: who sings a different world theme song season 6
[{'answer': 'Boyz II Men', 'provenance': [{'wikipedia_id': '589471', 'title': 'A Different World', 'start_paragraph_id': 75, 'start_character': 497, 'end_paragraph_id': 75, 'end_character': 508, 'bleu_score': 1.0, 'section': 'Section::::Connections to "The Cosby Show".\n'}]}, {'answer': 'Terrence Forsythe', 'provenance': [{'wikipedia_id': '589471', 'title': 'A Different World', 'start_paragraph_id': 75, 'start_character': 513, 'end_paragraph_id': 75, 'end_character': 530, 'bleu_score': 1.0, 'section': 'Section::::Connections to "The Cosby Show".\n'}]}]