Sound Stone

After all of the work I went through, this song better be good...

"Take a melody... Simple as can be... Give it some words and sweet harmony... Raise your voices, all day long now, love grows strong now, sing a melody of love, oh love."

—Eight Melodies, MOTHER 1

The Sound Stone is a specific type of MacGuffin which is an instrument, melody, music track, or part of a song which must be used or collected in order to achieve some purpose. Often a Sound Stone instrument must need another Sound Stone melody to work.

Very common in Video Games, especially RPGs. Often a form of Magic Music.

The Trope Namer is the Sound Stone, a plot-critical key item in EarthBound which collects and records eight melodies from around the world.

Examples of Sound Stone include:

Anime and Manga

• The Pink and Black Notes collected by My Melody and Kuromi respectively, in Onegai My Melody. Their MacGuffin nature is most prominent in Season 2: having collected a complete octave supposedly grants the owner a wish, but the two ditzes always waste the wish in nonsensicals, so that Status Quo Is God.
• The second Pokémon movie had a magical song that could calm the legendary birds, but will not work properly unless the magic spheres are placed in the temple. At the end of the movie, the whole temple turns into a music thing, with the pillars lighting as the different notes are played (and it conveniently gets offscreen when the song strays from those eight notes). Slightly subverted though, in that the "song" was just a duplication of Lugia's cry, and thus would (probably) not have been necessary if the titular Pokemon hadn't been incapacitated.
  • Rise of Darkrai (the tenth movie) also had a music disc that must be placed at the tower to keep the two Cosmic Horror-level Pokemon Dialga and Palkia from destroying the town of Alamos.
• Level Upper from A Certain Magical Index‍'‍s spinoff, A Certain Scientific Railgun. The only real trial is finding out what it is (a sound file that works using synthesia) and, after the protagonists do that, it serves no purpose anymore.

Live-Action TV

• The first season of Power Rangers had the Green Ranger's dagger flute, which he used to control the Dragonzord.
• Psych had an episode with a computer program that needed a quartet to work.
• Battlestar Galactica has "All Along the Watchtower" as its musical macguffin.

Video Games

• EarthBound is the Trope Namer. Ness carried an object called the Sound Stone, which recorded eight melodies from a series of Sanctuaries around the world to allow him to channel the Earth's power. The preceding installment, MOTHER, had an ocarina which Ninten used to play eight different melodies from his memory.
• The Zelda series has quite a few of these:
  • The Legend of Zelda Links Awakening
  • Ocarina of Time (obviously)
  • The Legend of Zelda Majoras Mask
  • Wind Waker
  • The Legend of Zelda Spirit Tracks
    • Pretty much every single Zelda game had a musical instrument of some sort. The Legend of Zelda had a Recorder that could reveal secrets. Zelda II the Adventure of Link had a magic flute that helps you progress. The Legend of Zelda a Link To T He Past had its own Ocarina which could be used to summon a neato bird that significantly cut down on travel time across the map. Even Twilight Princess had wolf calls. Musical instruments are always a little bit magical in the Zelda universe.
      • Oddly averted with The Legend of Zelda Phantom Hourglass, which is the only game in the series so far to lack an instrument of some shape or form.
      • The harp/lyre in The Legend of Zelda Skyward Sword
• Pokémon Red and Blue have the Poké Flute, which is needed to wake a sleeping Snorlax in order to pass. It can also be used to wake up your own Pokémon.
• Star Trek: The Next Generation — A Final Unity: The "orchestrions".
• Illusion of Gaia has Will's flute, which can play a few plot-relevant songs over the course of the game to help advance the plot.
• Queen: The eYe is about collecting these. Given that it's based on a band, that's hardly surprising.
• The Ar tonelico series has Hymn Crystals. When one of these crystals is Downloaded into a Reyvateil, it allows her to sing the Hymmnos Extract song contained within.
• Solatorobo has the Flute which is used to call the Master of the Clouds. Though it's not shown or referenced, whatever Red is using to collect the notes to buy songs he's heard likely counts as well.