A xylophone is near the end of the alphabet, but may be one of the first instruments a young child encounters. It consists of flat bars of wood or metal of different lengths, which produce different notes when hit using a mallet. Xylo is wood and phone is sound both parts of the word coming from Greek.
If I haven’t explained this particularly clearly, the English phrase “It’s all Greek to me” might be useful! After all, the Greek alphabet is different from ours. Instead of going from A to Z it goes from Alpha to Omega. Reference is made to it by Jesus in The Book of Revelation 22:13.