I don't know if this is the most famous and celebrated PFM's song, but IMHO it perfectly represents the kind of music this group wanted to make back in the seventies. As you probably remember, an english version of this track, titled Four Holes in The Ground also exists, featuring Pete Sinfield's allegoric lyrics. What I always liked in this song is the mediterranean soul, a warm athmosphere resulting in the perfect depiction of a summer night. The rythm has something ethnic in it, but the vocal parts are sweety european and you could get four good songs with the musical ideas of this track.
This is the album cover of "L'isola di niente".
I'll certainly spend some more words on other tracks taken from "L'isola di niente", for now I warmly invite you to a careful listening of this song: each time you put it in your CD reader you'll find something new. And this is exactly what a prog song should do.