He also recalls how people used to call him as "junior Anup Jalota".
"I have always followed him (Anup Jalota). In fact, when I used to sing in my school or anywhere else people used to say 'you are a junior Anup Jalota'," Sonu told reporters on Friday at the launch of a bhajan album "Divya Jyoti".
"I think he (Anup Jalota) did the work that even big legends have not done so far. He mesmerised everyone around the world with his bhajans and I was one of them," he added.
The 40-year-old, who started his singing career at the age of four, further said that his roots are in bhajans and that he learnt his first bhajan from his late mother Shobha.
"There is conception about me that I am a playback singer and I sing for albums or for films only, but my roots are in bhajans. Even when I was in school, I used to win competitions for ghazals and bhajans," said Sonu, known for singing songs like "Suraj hua maddham, and "Kal ho naa ho".
"My mother taught me my first bhajan. My mother Shobha Nigam was a very religious woman. From her only I learnt 'Om Jai Jagdish' song and used to do puja along with her," he recalled.