Sometimes, the Angel comes much later, because the children are naughty and won't learn their lessons or practise their scales.

And, sometimes, he does not come at all, because the children have a bad heart or a bad conscience.
No one ever sees the Angel; but he is heard by those who are meant to hear him.

He often comes when they least expect him, when they are sad and disheartened.

Then their ears suddenly perceive celestial harmonies, a divine voice, which they remember all their lives.
Persons who are visited by the Angel quiver with a thrill unknown to the rest of mankind.

And they can not touch an instrument, or open their mouths to sing, without producing sounds that put all other human sounds to shame.