How was the Legend of Zelda's main theme written?

The most famous adventure theme in games began as a licensing problem. As Shigeru Miyamoto and composer Koji Kondo recounted for the series' 30th anniversary, Kondo had been given a free hand on the title music for the 1986 original and settled on arranging Maurice Ravel's Bolero, whose long crescendo suited a journey perfectly. Very late in development the team confirmed the problem: Ravel had died in 1937, and under Japanese terms the work would not enter the public domain until fifty years after his death. It was still protected. The arrangement could not ship.

So Kondo wrote the replacement overnight. He built it from the musical material he had already composed for the game itself, the marching overworld music players would hear for most of the adventure, and the emergency title theme and the overworld theme fused into one identity: the melody that has now opened or underscored nearly every Zelda game since. Kondo has never pretended he foresaw any of it. Asked years later whether he expected to still be working the same theme decades on, his answer was a flat: not at all.

His favourite version, he told Polygon, is the Ocarina of Time overworld treatment, precisely because it solves the theme's occupational hazard, repetition. He broke the melody into eight bar sections that the game recombines with random phrasing, so the tune is always itself and never quite the same performance twice. A theme written in a single night to replace a borrowed one ended up, forty years on, as the thing other composers borrow.