How we cite our quotes: (Line)
Quote #1
And hark! the Nightingale begins its song,
'Most musical, most melancholy' bird! (12-13)
Coleridge quotes Milton here. If you've got to quote a poet, you may as well go for one considered a master. Milton clearly found the bird to be a sorrowful creature, and his verse became famous enough for others to quote. This prompts the speaker to recall the line when he hears the nightingale's song.
Quote #2
(And so, poor wretch! fill'd all things with himself,
And made all gentle sounds tell back the tale
Of his own sorrow) he, and such as he,
First named these notes a melancholy strain:
And many a poet echoes the conceit; (19-23)
The "poor wretch" is the poet who, with a broken heart, thought the nightingale sounded melancholy. In fact, everything he heard seemed to sound melancholy. The speaker blames the wretch's mood for the popular idea that nightingales have a sorrowful song, and he blames the poets who repeated for making it a popular idea.
Quote #3
Poet who hath been building up the rhyme
When he had better far have stretched his limbs
Beside a brook in mossy forest-dell, (24-26)
The poet would have been better to spend time outside, says the speaker. Instead of creating rhymes indoors, the poet should lie in the grass near a brook and take it all in. Well, we guess a famous poet like Coleridge is qualified to give a piece or two of poetic advice.