It's a major-key sound, but unlike our major keys, which have a half step between the third and fourth tones, the Lydian scale has a whole step there, and the half step between steps four and five.

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Piano keys each have three strings that, when struck by a felt-covered hammer, make a musical sound. (The exceptions are the bass keys, which have either two strings or one.) Pressing the soft pedal shifts the hammers so only two of the three strings are touched, giving the piano a much softer tone.

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Another cool feature: Sound is louder when you the virtual keys or drums harder.

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Florian Schneider, a founding member, played the calculator, which was wired into the sound system, so that pressing the keys made audible beeps.

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But to achieve that sound required a heavier action, resulting in keys that were harder to push down.

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With his own acclaimed bands (Gnarls Barkley, Broken Bells) and his production work for others (Gorillaz, Beck, the Black Keys, lately U2), his sound has become highly sought in recent years.

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