He received a fresh lease of life in his playback singing career from 1971 after Rajesh Khanna allowed music directors to picturise or feature songs sung by Dey in films with Khanna in lead role beginning with Anand, composed by Salil Chowdahry. For Rajesh Khanna, Dey had sung songs "Zindagi kaisi hai paheli" (Anand, 1971), "Tum bin jeewan kaisa jeewan" and "Bhor Aaye Gaya Andhera" (Bawarchi, 1972), "Nadiya Chale Re" (song sung with Rajesh and Dey), "Hasne ki chah ne kitna mujhe" (Avishkaar, 1973) and "Gori tori paijaniya" (Mehbooba, 1976). Later in a 2012 interview, Dey said, "I loved the way he picturised music. The success of a song depends upon how an actor picturises it. He was the number one in picturising songs. I will be ever indebted to him." From 1970 to 1983, he recorded around 503 songs used in Hindi films. Thereafter he became selective of the kinds of songs he sings and chose to do less work in Hindi.
