Reed Pipes are a type of musical instrument used by satyrs. When satyrs play certain magical songs, the reed pipes can help them in many ways such as growing plants, capturing enemies, and keeping away insects and other pests. It is also Pan's main symbol of power.
Grover Underwood, who is Percy Jackson's best friend, went with him on his Quest for Zeus' Master Bolt. During this, Grover tried to work his reed pipe to help them, but it just sounded bad as he only knew two songs - a Mozart symphony and Hilary Duff's 'So Yesterday' - and a tracking song at the time. At Camp Half-Blood, satyrs used them to scare bugs away from the strawberry fields.Zoë Nightshade and Bianca di Angelo, but instead created poison ivy. Grover also uses it to play a Barry Manilow song as a confusion spell to confuse the security guards in the Smithsonian museum. Later, at The Junkyard of the Gods, Grover uses them for a tracking spell and again to fight a defective prototype of Talos, making power lines come to life and electrocute it.
Grover uses it to open a pathway known as Orpheus' doorway to the Underworld for Percy and Nico di Angelo. Along with other satyrs, Grover used his reed pipes to imprison Hyperion in a maple tree. During the Battle of Manhattan, the satyrs used their reed pipes to combat the titan Hyperion and his army. The satyrs imprisoned Hyperion in a maple tree. Grover also used it against Kronos on Olympus to create plants to intertwine his legs, but Grover stopped playing too soon and the magic was too weak to slow Kronos down and was broken.
Reed Pipes are usually used by satyrs or fauns to play magical songs. However, satyrs and fauns can use the music generated by these pipes to channel their woodland magic. This magic can be used for tracking spells, blessings, or even grow trees to encase enemies. It is a satyr's main weapon, even if satyrs aren't usually very violent fighters. It is shown that when the satyrs play their reed pipes together they can channel powerful woodland magic.