If the winter day is cold enough, the sound of the music will go unheard, because it freezes in the air. Then when Spring comes, and the temperature rises, the music will thaw. People passing at that time will hear the melody, but the musician and her cello will have been long since gone.
A similar acoustic phenomenon once happened to the famous Baron Munchausen, who played some notes on a cold winter day on his French horn (or was it a bugle?) on a hunting trip.