Analysis of Is This the Lark!

Is this the lark
Lord Shakespeare heard
Out of the dark
Of dawn! Is this the bird
That stirred
Lord Shakespeare’s heart!

Is this the bird whose wing,
Whose rapturous antheming,
Rose up, soared radiant, became
Sharp flame
To Shelley listening
And made him sing,
Throbbing alone, aloof, feveredly apart,
His profuse strains of unpremeditated art!

To think that I should hear him now
Telling that single fiery rift of heaven a wild lark comes! …
The fresh cool scent of earth yearns at the plough;
In short keen rapid flurries the woodpecker drums….
To think that I should hear that mad thing sliding
Along a smoking opal ladder!
Hear that inevitable deluge of music riding
Into the sun, richer now—fainter now—madder!
To think that I should hear and know
The song that Shelley heard, and Shakespeare, long ago!