Analysis of The Late Singer

Here it is spring again
and I still a young man!
I am late at my singing.
The sparrow with the black rain on his breast
has been at his cadenzas for two weeks past:
What is it that is dragging at my heart?
The grass by the back door
is stiff with sap.
The old maples are opening
their branches of brown and yellow moth-flowers.
A moon hangs in the blue
in the early afternoons over the marshes.
I am late at my singing.