It is close to impossible to explain the concept of silence in music to someone lacking much music listening experience. Personally I would divide this silence into two:
a) Background silence which must exist in order for music to reach the listener without accompanying unrelated thoughts. This is why it is impossible to listen to music as the background of something. You may hear it, but you cannot listen to it.
b) Silence between sounds. It is like a full stop between sentences in a good book, with a purpose to urge you on to the next sentence, all the while giving you an opportunity to absorb the previous sentence and create connections in your fantasy world.
Creating silence in music is a master class for both the composer and interpreter, as the duration and character of that silence is so strongly connected with the character of the musician, the instrument and the room. Thus choosing the correct tempo is really a decision over the duration of silence.
Listening to the silence is a master class of its own for the audience. Are those pauses justified? A sigh perhaps? Sad and controversial … massive gaps? At any rate they are certainly moments that the listener provides content for in his or her head. A fragment of eternity of which one could get a part of.
Photo: Bartosz Woroch in St. John Smith Square