90s · Playback · Sonu Nigam
The 1990s did something strange to the playback voice
Between Kishore's death and Arijit's arrival, Hindi film singing moved closer to the microphone and further from the orchestra. You can hear the seam.
Golden-era playback was sung to a room. The orchestra was large, often recorded live with the singer, and the vocal had to carry over it. That is why Rafi and Lata phrase the way they do: everything is projected, because the alternative is being buried.
By the mid nineties the room was gone. Tracks were layered, the singer arrived to a finished bed, and the microphone was close. The voice stopped projecting and started confiding. Meri Duniya Hai is sung at conversational volume for most of its length and only opens up when the film needs it to. Mujhe Raat Din does the same thing with a pop structure underneath.
The transition is audible if you go back a decade to Neele Neele Ambar Par. Kishore Kumar in 1983 is already singing softly, but he is still singing to a space. The nineties singers are singing to a listener wearing headphones, a decade before most of them were.
Neither approach is better. But it explains why golden-era recordings reward a good speaker and nineties recordings survive a phone, which is most of how both get heard now.