[GolDDranks]

This is not true in a strict sense; Standard Japanese has a pitch accent that has a "culminative" pitch countour over a word. Culminativity means that there is a single point of prominence at maximum. In Japanese, this gets realised as a drop in the pitch. (In variants of Japanese, there are more elaborare systems.)

Tone systems are different in the sense that each syllable has it's own countour. (Of course, when realized, these get merged according to various phonological processes) Japanese differs from tone systems in that it has only one culminative pitch contour over multi-syllable words.

(Disclosure: I am an expert in Japanese phonology, especially in pitch accent.)

[throwaway2037]

    Disclosure: I am an expert in Japanese phonology, especially in pitch accent.

+9000. Please post more!

[GolDDranks]

Not sure what to post, but here are four interesting tidbits about Japanese pitch accent:

1) "Culminativity" is actually considered the most helpful functionality of the pitch accent. It helps making sense of word boundaries, as there can be only one prominent syllable per word. In spoken word of any language, there are no "spaces" (there are no spaces in written Japanese either, though), so languages need to provide accommodations for aural parsing strategies.

2) The other functionality provided by the pitch accent is distinctiveness, which means that there are some homonyms (similar-sounding words), that are only differentiated by the pitch accent. However, that is only a secondary functionality. In Mandarin Chinese, tones play a lot more important role for making sense of the meaning of the word. In Japanese, they play a role, but not a significant one. (There are some hundreds of minimal pair words that differ only by the pitch accent pattern, but as many regional dialects also have slightly different accent patterns, clearly 100% nailing the pattern isn't required for communication, as long as the general principles (such as one drop per word) are followed.)

3) Japanese is said to be an "isochronic" language, which means it has (or at least, is perceived to have) a simple integer-based rythm. For example, Haiku, a famous genre of Japanese poetry is based on these rythms, unit of which is called haku (拍) in Japanese or mora in Latin/English. In context of poetry metrics, mora is often misrepresented as a "syllable", but actually, there are uni- and bimoraic (and rarely, trimoraic) syllables in Japanese. An example: 2-mora "ma-to" means a target (in archery etc). 3-mora "ma-t-to" means a "mat/carpet". 3-mora "ma-n-to" means a cloak. 3-mora "ma-to-o" meas "let's wait". 3-mora "ma-to-n" means "mutton meat". 4-mora "ma-t-to-o" means "proper/straight". But every one of these are two-syllable words!

4) The rythm of Japanese speech is not concerned with the pitch accent prominence, unlike stress in English, which tends to make stressed syllables longer and louder (and more defined in vowel quality). Indeed, it is often said that "syllables" are an irrelevant concept for Japanese. However, phonologically that isn't true at all. The rythm of Japanese is indeed dependent mostly on moras, but the pitch accent patterns, where the prominent drop of pitch tends to happen, is highly dependent on syllable structure. It never happens on "weak" morae, which are called the "coda" or tail of the syllable. It always happens on the start of a syllable.