WB Yeats - on a public bus?

So the other day I was testing out the public transportation system around here. While on a bus coming back from the train station (the trains here are very spiffy, by the way), I noticed that there was a Yeats poem inscribed on the ceiling of the vehicle.

Struck by its incongruity in such a work-a-day location, I set about memorizing it, and succeeded(it's a very short poem, after all) before I was back at the school.

Here is the poem, in its entirety. I don't remember the title, but I do recall everything else:

I made my song a coat,
Covered with embroideries
Out of old mythologies
From heel to throat;
But the fools caught it,
Wore it in the world's eyes
As though they'd wrought it.
Song let them take it,
For there's more enterprise
In walking naked.

It's a very simple one, and not hard to catch the meaning of. Yeats "invented" his own style, involving imagery from mythology and ancient legends, but it was imitated by his contemporaries as though it was their own. Their poems, Yeats implies, are worth little, because they are devoid of the meaning which makes his poems able to stand even without adornment.

It's not my favorite poem of all time, but I'm always rather fond of Yeats' style - the language he employs, the interesting patterns of the lines. And where I found it was so strikingly unusual....

Such findings are always neat, just by virtue of their unexpectedness.