Salma, who lent her poignant voice in classic songs like "Dil ke armaan" and "Fiza bhi hai", has sang for Indo-Norwegian collaboration film "Dunno Y 2... Life Is a Moment".
"Anybody can make a comedy movie like 'Dostana'. If you make a serious film on subject it's a hard job," Salma said at a music interaction here.
"It's a challenging job for both the actor and director to make a film on such a sensitive issue. You have to be a fine director. Just anybody can't do that. Portraying a character like this for a normal man is not an easy task to do," she added.
Salma, who is extremely choosy in singing for films, agreed to sing in this project only on the condition that the music and the lyrics of the song should touch her heart.
Talking about her song in the film, she said: "This song is a Sufi Ghazal, 'Aaina haseen hua hai, ishq hai ahsaah mein, tere hone ki aas mein'. When I heard the song, I instantly felt as if it touched my soul."
Another song in the film "Jeena kya hai, jaana maine, jabse tumko jaana" is performed by legendary singer Lata Mangeshkar.
Salma, who last sang for a Bollywood film in 1994, said she stayed away from the industry for long for her family and children's education.
"It was the situation that time I went abroad for my family and children's education but now I am back," she said.
"Dunno Y 2...Life Is A Moment" is a sequel of "Dunno Y...Na Jaane Kyun". The film is set in Norway, where same sex marriage is legal.
