Question: who is the singer of kal ho na ho
[{'answer': 'Sonu Nigam', 'provenance': [{'wikipedia_id': '32202531', 'title': 'Kal Ho Naa Ho (song)', 'start_paragraph_id': 1, 'start_character': 92, 'end_paragraph_id': 1, 'end_character': 102, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Alka Yagnik', 'provenance': [{'wikipedia_id': '32202531', 'title': 'Kal Ho Naa Ho (song)', 'start_paragraph_id': 1, 'start_character': 290, 'end_paragraph_id': 1, 'end_character': 301, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Richa Sharma', 'provenance': [{'wikipedia_id': '32202531', 'title': 'Kal Ho Naa Ho (song)', 'start_paragraph_id': 1, 'start_character': 306, 'end_paragraph_id': 1, 'end_character': 318, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'also a sad version of the song in the film on which Sonu Nigam is joined by Alka Yagnik and Richa Sharma'}, {'provenance': [{'wikipedia_id': '32202531', 'title': 'Kal Ho Naa Ho (song)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['"Kal Ho Naa Ho" ( Tomorrow may never come) is a 2003 Hindi-language filmi song performed by Sonu Nigam for the 2003 Indian romantic drama film of the same name. The track was composed by ShankarEhsaanLoy, while lyrics were written by Javed Akhtar. In a pathos version, Nigam is joined by Alka Yagnik and Richa Sharma.', '"Kal Ho Naa Ho" ( Tomorrow may never come) is a 2003 Hindi-language filmi song performed by Sonu Nigam for the 2003 Indian romantic drama film of the same name. The track was composed by ShankarEhsaanLoy, while lyrics were written by Javed Akhtar. In a pathos version, Nigam is joined by Alka Yagnik and Richa Sharma.', 'The track was composed by ShankarEhsaanLoy, while lyrics were written by Javed Akhtar. In a pathos version, Nigam is joined by Alka Yagnik and Richa Sharma. "Kal Ho Naa Ho" was directed by Nikhil Advani and written by Karan Johar; the latter co-produced it with his father Yash Johar under the banner of Dharma Productions.']}}]}]