Moonbell is an automated music generator that plays musical scores based on lunar topographical data obtained by Japan's Kaguya (SELENE) explorer during its orbit around the moon from late 2007 to June 2009.
Moonbell, which was developed in cooperation with the Japan Aerospace Exploration Agency (JAXA), has two playback modes: "Orbit Play" and "Free Scratch." Click the buttons on the bottom right of the screen to switch modes.
In Orbit Play mode, Kaguya traverses the moon in a circular orbit and music is generated based on the topography below. This screen displays Kaguya's orbital path, an altitude graph of the topography, and the corresponding musical notation map. Use your mouse to change Kaguya's location and orbit.
In Free Scratch mode, you can use your mouse to chart a path across the moon's surface. The corresponding music plays in a loop, regardless of how long the path is. The notes are visualized as different colors and patterns on the screen.
To tweak the audio output, click the "Preference" button on the bottom left of the screen. This opens the settings panel, where you can choose from 128 musical instruments for each track, change the playback speed, set the volume for each instrument, and more.
See the "About" page for a complete description of all of Moonbell's functions and controls.