Who is the lead singer of Nirvana?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q30', 'id': 0, 'label': 'United States of America'}, {'type': 'INTERNAL', 'name_': 'Q145', 'id': 1, 'label': 'United Kingdom'}, {'type': 'INTERNAL', 'name_': 'Q21077', 'id': 2, 'label': 'Warner Music Group'}, {'type': 'INTERNAL', 'name_': 'Q22151', 'id': 3, 'label': 'Muse'}, {'type': 'INTERNAL', 'name_': 'Q28936', 'id': 4, 'label': 'Cloud Atlas'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q126399', 'id': 5, 'label': 'Warner Bros.'}, {'type': 'INTERNAL', 'name_': 'Q1542129', 'id': 6, 'label': 'Grammy Award for Best Alternative Music Album'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q11649', 'id': 7, 'label': 'Nirvana'}], 'links': [{'name_': 'P17', 'source': 0, 'target': 0, 'label': 'country'}, {'name_': 'P530', 'source': 0, 'target': 1, 'label': 'diplomatic relation'}, {'name_': 'P530', 'source': 1, 'target': 0, 'label': 'diplomatic relation'}, {'name_': 'P17', 'source': 1, 'target': 1, 'label': 'country'}, {'name_': 'P17', 'source': 2, 'target': 0, 'label': 'country'}, {'name_': 'P112', 'source': 2, 'target': 5, 'label': 'founded by'}, {'name_': 'P495', 'source': 3, 'target': 1, 'label': 'country of origin'}, {'name_': 'P737', 'source': 3, 'target': 7, 'label': 'influenced by'}, {'name_': 'P495', 'source': 4, 'target': 0, 'label': 'country of origin'}, {'name_': 'P495', 'source': 4, 'target': 1, 'label': 'country of origin'}, {'name_': 'P750', 'source': 4, 'target': 5, 'label': 'distributed by'}, {'name_': 'P17', 'source': 6, 'target': 0, 'label': 'country'}, {'name_': 'P1346', 'source': 6, 'target': 7, 'label': 'winner'}]}