The Greek god Apollo was the god of light, order, arts and muses, reason, prophecy. He was the son of Zeus and Leto and the twin brother of Artemis. He is represented as a young and handsome man, sometimes in a chariot, given to him by his father, Zeus.
When Hera found out that her husband had had another affair, she sent a monstruous serpent, the Python, to follow Leto day and night, so as she could have no peace to have her children (she was bearing twins).
But Leto made it to the island of Delos, where she gave birth to Artemis. The mother was too tired to have the second baby, but precocious Artemis helped her to give birth to Apollo. The father gave both children bows and arrows, as gifts.
The Greek god Apollo was a precocious baby, too. He was only four days old when he followed and killed the Python as a revenge for having given a hard time to his mother.
But the Python was the son of the goddess Gaia, so Apollo had to pay for his crime. He had to become king Admetus' servant for one year. King Admetus treated him well, so Apollo told him that, when time came for him to die, he could continue to live if he could find someone else to die in his place (now if you ask me, I think this is a very selfish thing to do, ask someone else to die in your place).
One day, Niobe, the queen of Thebes, started to laugh at Leto, who only had two children, while the queen had seven girls and seven boys. Leto was offended by all this, so she told her children about it. The revenge was scary: the Greek god Apollo killed with his arrows Niobe's seven sons, while the goddess Artemis killed the daughters (ok, so Niobe had a child-like reaction, but the other two were gods, they should have been above all these small human things).
One of the Greek god Apollo's surname was the Musagetes, that is "the leader of the muses". In the paintings below, he is represented together with the nine muses.
When his half brother Hermes invented the lyre, Apollo liked the sound of it so much, that he exchanged his immortal cattle for it. Later, he took from Hermes the pan-pipe, in exchange for his golden wand. The Greek god Apollo was a very good player and he was convinced no one played better than him.
In a contest with the god Pan, king Midas was in the jury. Pan played some rustic melodies and everyone liked them. Then it was Apollo's turn, and everyone agreed that Apollo was the best. All, except Midas - to whom Apollo gave a pair of donkey ears, for the way he had judged the god's music.
Another one who challenged Apollo was the satyr Marsyas, who played the flute better than the god played the lyre. But Apollo had a bright idea which allowed him to win the contest: he suggested for them to play their instruments upside down. Marsyas protested because this was not a part of the initial understanding, but of course the Greek god Apolo had it his way. Poor Marsyas lost and the god of light and order skinned him alive.