In the World of Greyhawk campaign setting

Campaign setting

A campaign setting is usually a fictional world which serves as a setting for a role-playing game or wargame campaign. A campaign is a series of individual adventures, and a campaign setting is the world in which such adventures and campaigns take place...

 for the Dungeons & Dragons

Dungeons & Dragons

Dungeons & Dragons is a fantasy role-playing game originally designed by Gary Gygax and Dave Arneson, and first published in 1974 by Tactical Studies Rules, Inc. . The game has been published by Wizards of the Coast since 1997...

role-playing game

Role-playing game

A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

 Heward's Mystical Organ is a powerful artifact, the creation of the hero-deity Heward

Heward

In the World of Greyhawk campaign setting for the Dungeons & Dragons role-playing game, Heward is the god of Bards and Musicians. Heward is notable not only for his musical prowess, but also for his technological skills....

.

Description

Heward's Mystical Organ is a massive pipe organ the size of a large room. Playing different keys in specific orders can cause any number of different magical effects.

Dungeons & Dragons (1974-1976)

Heward's Mystical Organ first appeared in the fourth supplement to the original D&D rules, Eldritch Wizardry

Eldritch Wizardry

Eldritch Wizardry is a supplementary rulebook by Gary Gygax and Brian Blume, written for the original edition of the Dungeons & Dragons fantasy role-playing game, which included a number of significant additions to the core game.-Contents:...

(1976).

Advanced Dungeons & Dragons 1st edition (1977-1988)

Heward's Mystical Organ was also mentioned in the original 1979 Dungeon Master's Guide

Dungeon Master's Guide

The Dungeon Master's Guide is a book of rules for the fantasy role-playing game Dungeons & Dragons...

. A system to generate magical effects for the musical artifact was given in The Dragon

Dragon (magazine)

Dragon is one of the two official magazines for source material for the Dungeons & Dragons role-playing game and associated products, the other being Dungeon. TSR, Inc. originally launched the monthly printed magazine in 1976 to succeed the company's earlier publication, The Strategic Review. The...

#29 (September 1979) in the "Bazaar of the Bizarre" column.

Advanced Dungeons & Dragons 2nd edition (1989-1999)

Heward's Mystical Organ was detailed in the second edition Dungeon Master's Guide (1989). It was further developed in 1993's Book of Artifacts

Book of Artifacts

The Book of Artifacts is a supplemental sourcebook to the core rules of the second edition of the Advanced Dungeons & Dragons fantasy role-playing game. This book, published by TSR, Inc. in 1993, details 50 different artifacts, special magic items found within the game at the Dungeon Master's...

. It also appeared in the fourth volume of the Encyclopedia Magica

Encyclopedia Magica

The Encyclopedia Magica is a series of four volumes of accessories for the 2nd edition of the Advanced Dungeons & Dragons fantasy role-playing game, published in 1994-1995....

series (1995).