You would never hear any song played twice in the same way. The words were retained, but within a certain frame there was great latitude, and the musician could improvise to his heart's content; and the more the variations and combinations, the greater the musician.
Rhythm and harmony enter most powerfully into the inner most part of the soul and lay forcible hands upon it, bearing grace with them, so making graceful him who is rightly trained.
In Haydn's oratorios, the notes present to the imagination not only motions, as, of the snake, the stag, and the elephant, but colors also; as the green grass.