Today I accidently learned why Pan flute is called Pan flute. While reading a book, I came across a Greek god called Pan. As I had never heard of him before, I checked up his description on Wikipedia and it turns out that as per Greek myth, he is the one who invented the Pan flute and used to play it; therefore, the flute composed of many adjacent straws was identified through him.
And here is what Wikipedia specifically has to say about him and his flute, “In Greek religion and mythology, Pan is the god of the wild, shepherds and flocks, nature of mountain wilds and rustic music, and companion of the nymphs. His name originates within the Ancient Greek language, from the word paein (πάειν), meaning “to pasture.” He has the hindquarters, legs, and horns of a goat.
One of the famous myths of Pan involves the origin of his pan flute, fashioned from lengths of hollow reed. Syrinx was a lovely water-nymph of Arcadia, daughter of Landon, the river-god. As she was returning from the hunt one day, Pan met her. To escape from his importunities, the fair nymph ran away and didn’t stop to hear his compliments. He pursued from Mount Lycaeum until she came to her sisters who immediately changed her into a reed. When the air blew through the reeds, it produced a plaintive melody. The god, still infatuated, took some of the reeds, because he could not identify which reed she became, and cut seven pieces (or according to some versions, nine), joined them side by side in gradually decreasing lengths, and formed the musical instrument bearing the name of his beloved Syrinx. Henceforth Pan was seldom seen without it.”