FM synthesis can create both harmonic and inharmonic sounds. But if there are inharmonic partials, the numbering no longer coincides. These chaotic models create compositions from the harmonic and inharmonic phenomena of nature. An inharmonic partial is any partial that does not match an ideal harmonic. For example, a harmonic sound could be restructured to sound inharmonic, and vice versa. Many percussion instruments, such as cymbals, tam-tams, and chimes, create complex and inharmonic sounds. An inharmonic frequency is a non-integer multiple of a fundamental frequency.