Question: who has sung more than one bond theme
[{'answer': 'John Barry', 'provenance': [{'wikipedia_id': '1284911', 'title': 'James Bond music', 'start_paragraph_id': 7, 'start_character': 95, 'end_paragraph_id': 7, 'end_character': 105, 'bleu_score': 1.0, 'section': 'Section::::"007 Theme".\n'}]}, {'answer': 'Shirley Bassey', 'provenance': [{'wikipedia_id': '1284911', 'title': 'James Bond music', 'start_paragraph_id': 1, 'start_character': 368, 'end_paragraph_id': 1, 'end_character': 382, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]