WVA-I heard (alas! 'twas only in a dream)

I heard (alas! 'twas only in a dream)
Strains--which, as sage Antiquity believed,
By waking ears have sometimes been received
Wafted adown the wind from lake or stream;
A most melodious requiem,--a supreme
And perfect harmony of notes, achieved
By a fair Swan on drowsy billows heaved,
O'er which her pinions shed a silver gleam:--
For is she not the votary of Apollo?
And knows she not, singing as he inspires,
That bliss awaits her which the ungenial hollow*
Of the dull earth partakes not, nor desires?
Mount, tuneful Bird, and join the immortal quires!
She soared--and I awoke,--struggling in vain to follow.

* See the Phedo of Plato, by which this Sonnet was suggested.