A flower was offered to me;
Such a flower as May never bore.
But I said I've a Pretty Rose-tree:
And I passed the sweet flower o'er.

Then I went to my Pretty Rose-tree;
To tend her by day and by night.
But my Rose turnd away with jealousy:
And her thorns were my only delight.

———————-
On one level, the poem seems to be about a married man resisting the temptation of another woman, and his wife being offended he should have ever been tempted in the first place.

On another level, though, it is suggested that the first woman, ‘such a flower as May never bore’, was not an earthly love but a spiritual one - see https://en.wikipedia.org/wiki/The_Lilly_(poem)

My Pretty Rose Tree - William Blake (in song)

For the best experience, 
-  Click on the song's picture for words and notes.
-  in Album/Playlist/Spotlight, first click on the big picture to the left, then on the new page click the track title. Really, it's worth the effort :) 

With Blake you will see his painting too. Each picture is in dialogue with the words (not just illustrating them).

Bards have combined music & poetry from earliest times. Many poets continue the connection, not least William Blake. But often their melodies are lost or neglected.

My Pretty Rose Tree - William Blake (in song)

Ian