The title? It's "Romance Sonambulo." 'Nuf said, right? Ah, we can see by the looks on your faces, Shmoopers, that perhaps that's not enough at all.
Never fear. Shmoop's got your back. First of all, the title is in Spanish, so that's something to keep in mind. The English translation of the title typically is "Somnambulist Ballad," which is, we're guessing, not exactly all that much clearer. So, let's start with the "Romance," or "Ballad" part first. That's pretty clear. This poem is a ballad, and so the title lets us know that. Thanks, Lorca. Very helpful of you. (For more on what's involved in a ballad, check out "Form and Meter," then click back here.)
Now for the tricky part. "Sonambulo," or the English translation, "Somnambulist," refers to someone who sleepwalks. Now, go write that word down, Shmoopers, and use it tomorrow in casual conversation to blow your friends and neighbors away with your wild vocab skills. So, more directly, we might call this poem "The Ballad of the Sleepwalker." Is it getting clearer?
Certainly, after you read all the dreamy images here, you'll see what Lorca is getting at. This is actually a very old form of poetry (a ballad) that's told through a very cutting edge (at the time) approach to art, namely surrealism. Surrealists drew on the imagery and disconnection of dreams as an innovative way to express themselves (check out "Calling Card" for more on Lorca's surrealism). So, the title just lets us know that we're in for: a dream-like trip, taken in an old-timey vehicle.