My gift is gaining. Call it paradox. The thing I do not have, a yellow bird, I gladly give and gain it. I take it from a purple tree With purple boughs and leaves.
Or take it from some oak so ordinary, Slanting towards the street, Not even birds remember it, Not even birds with bleached brown wings.
But gained I give it up, Because the yellow bird was there And what I give I gain.
The speaker is a painter, and the whole poem circles one puzzle: how can giving something away be a way of gaining it? He begins with a yellow bird he doesn't actually possess. By painting it, he "gives" it to the world, and in the act of giving he finds he has it after all. The title suggests this is his own song, a kind of private creed about how art works.
The second stanza shifts from the dazzling to the dull. A purple tree, vivid and invented, is one place the bird can come from, but so is a plain oak leaning toward the street, one that even birds have forgotten. The painter doesn't seem to care whether his material is grand or ordinary. What matters is the exchange itself.
The mood is calm, playful, and quietly pleased with itself. The last lines loop back on themselves, as if the logic were a small closed circle: the bird was there, so giving it up costs him nothing.