The Rhythm League

The Rhythm League (なぞのリズム組織) is a mysterious organization in the Rhythm Heaven Series. Being mysterious, not much is known about them, aside from them being the ones who rate the player's performance in the various Remixes.

Members
The known members are characters from the various Rhythm Games, though it's implied there are many more.

Chairman of the Rhythm League

 * Main article: Space Gramps

The Chairman of the Rhythm League (なぞのリズム組織代表) is Space Gramps. He sends a letter to the player to congratulate them on getting a Perfect in Remix 8, and an award for performed outstandingly at the Rhythm Rally Table Tennis Tourney.

Rhythm League Advisor

 * Main article: Captain Blue Bird

The Rhythm League Advisor (謎のリズム組織 特別顧問) is Captain Blue Bird. He writes a letter to the player, congratulating them for perfecting Remix 10.

The Wrestler's Rhythm League Fan Club Rep.
The Wrestler's Rhythm League Fan Club Rep. (謎のリズム組織　レスラー友の会　代表より) is an unseen character who writes a letter to the player, congratulating them for perfecting Remix 10, and telling them about the two-player mode. Although most languages specify the identity of this individual, the 🇺🇸 and versions leave it ambiguous.

Other mentions

 * On August 3, 2006, the Sick Beats Doctor received a vial from the mysterious Rhythm League, which contained Microbes, all moving in time.
 * Although the Rhythm League still rates the player's performance in Rhythm Heaven Megamix, at no point in the game does a representative send any letters to the player. Space Gramps, Captain Blue Bird and the Wrestler all appear in their respective Rhythm Games.