It's especially good to read this poem in the northeast, after the solstice, when indeed Hardy's landscape description seems dead-on. I love that he claims he's able to see that this particular singing bird is "aged." It would probably take a keen eye and a profound ornithological knowledge to determine that! But of course Hardy knows we know that, and so the adjective points to a certain playfulness in that over-the-top description of the poor battered singer. I think we're supposed to know that there's a least a little grace-note of comedy (in the form of an ironic self-awareness) here.

But I wanted to point to an earlier 19th century thrush, whose message to the listener's a bit different. It's another bird from Keats, of course:

What The Thrush Said

'O thou whose face hath felt the Winter's wind,
Whose eye has seen the snow-clouds hung in mist,
And the black elm tops 'mong the freezing stars,
To thee the spring will be a harvest-time.
O thou, whose only book has been the light
Of supreme darkness which thou feddest on
Night after night when Phoebus was away,
To thee the Spring shall be a triple morn.
O fret not after knowledge–I have none,
And yet my song comes native with the warmth.
O fret not after knowledge–I have none,
And yet the Evening listens. He who saddens
At thought of idleness cannot be idle,
And he's awake who thinks himself asleep.'

Surely it's no accident that Hardy's final phrase describes that "blessed hope whereof he knew/ and I was unaware." Hardy might well have called his poem "What the Thrush Knew" -- and that "I was unaware" plays beautifully off Keats' last line.