I sing to him that rests below,
  And, since the grasses round me wave,
  I take the grasses of the grave,
And make them pipes whereon to blow.

 ... 

 ... 
  I do but sing because I must,
And pipe but as the linnets sing:

And one is glad; her note is gay,
  For now her little ones have ranged;
  And one is sad; her note is changed,
Because her brood is stol'n away.