The "slowest" language, Mandarin, partly thanks to the four tones, has around 2000 possible syllables, far more than Japanese or Spanish.

语速最慢的汉语普通话有大约2000个音节，比日语和西班牙语多得多。有四个音调也是普通话语速慢的部分原因。

youdao

Mandarin, the biggest language in the Chinese family, has four tones, so that what sounds just like "ma" in English has four distinct sounds, and meanings.

汉语中最大的分支普通话有四种声调，所以英语中的“ma”在汉语中就有四种不同的发音，以及各不相同的意思。

youdao

By the end of the first semester, I was still terribly confused about the four tones of spoken Chinese, and the voices from the tape were simply a din.

第一学期末，我还是对中文四声的发音摸不着头脑，磁带里中文对话从头到尾都是哇啦哇啦。

youdao

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.

WSJ: Making Music Against the Odds | Ensembles of Afghanistan National Institute of Music