Toward the end, he reveals that his dream was inspired by his lover's eyes "which are blue like a sky studded with stars" (Che sono blu come un cielo trapunto di stelle). And the music he hears is his lover's voice.
Nel Blu, Dipinto di Blu (into the blue, painted blue)--Domenico Modugno (1958)
Ah such innocent times, charming lyrics sung by guys in coat and tie.. glad to have experienced the pre-British-Invasion music era..