It is very measured melody of the classical genre. It fills us with expectation of something beautiful and pure for all of its nearly 2 minutes without 3 seconds. Just like the clear sky in frosty morning that you're looking at with a cup of fiery hot coffee in the hands, which are dressed in woven gloves with the finger-top cut out. The main theme is given by a piano sound, which is the mostly noticeable. And the violin comes closer to completion.
Reference:Interview: Nick Urata