I can think of at least two ways this helps out musicians greatly. The first obvious thing is when you focus on your playing in the recording, you can hear your mistakes or the areas that 'need improvement.'Wooferhound wrote:It is important for the players to hear the music when they aren't playing and thinking about it.
But the second thing, which I think is less obvious, is you can hear what the other people are doing and analyze your playing in relation to what the other musicians are doing. Not as easy to do 'live' without some playing experience, in my opinion.
For example, if you hear the other guitar player playing the same chord positions you are, think about what you could play instead, or if you hear the bass player put in a little riff can you do something that sounds cool with it? It gives you the ability to focus on what the others are doing and to think about what you can do to make it better.