I always felt I had an instinct for playing the right record at the right time. It seemed to be easier at night than during drive time. By playing the right record I mean the right tempo, the right mood of the song etc. Or course feedback from the telephone always helped. I think most good DJs had or developed this instinct. I don't know how the DJs doing voice tracking can even come close. They do try all kinds of tricks to make it seem live but it's not. When a significant news event happens or a drastic unexpected change in the weather all demand "live" DJ interaction.
This instinct became even more important during the disco age. The ability to get the audience dancing and keep them dancing and know when they needed a slow song break was key to a good club or portable D.J.