The "Kal Ho Na Ho" singer feels every generation tries to imbibe something from their previous generation and add their own touch in music.
When asked about the way music has changed today in comparison with 90s, Sonu told reporters, "Of course music has to change. Our society changes, even the dressing sense changes... Everything changes, including the languages.
"I believe every generation tries to learn something from the previous one and tries to go one step ahead.
We learnt from our gurus and then added our touch to what we were doing... Music has definitely changed and will keep on changing."
The 43-year-old singer was speaking at a press conference of "Indian Idol", last night.
The ninth edition of the singing reality TV show brings back Anu Malik, Sonu Nigam and Farah Khan as judges.
They were the original trio who started judging "Indian Idol" almost 12 years ago.
Malik said one first day of shoot, it didn't not feel like they were coming back after 12 years but as if "it was only yesterday that we shot season one."
Farah said while the aim of the judges is to still choose the perfect singer, there has been a slight change in them when it comes to the basis of selection.
"12 years ago, we used to be rigid. 'Oh he's not an all round singer, he sings only classical, so he can't sing western.' But we have realised this is their genre, their forte.
"A classical singer need not sing a rock and roll song. Even we have changed our outlook," Farah said.
To which, Sonu added, "I haven't seen such good quality of singers before. I am really proud of the fact that we have some great singers this time."
"Indian Idol" season nine will be hosted by Karan Wahi and Paritosh Tripathy. It will air on Sony from December 24.