Pitch, tone, and stress

[SGP]

In Chinese, "ma", with different tones may mean mother, horse or question.

"Ma" might be the most prominent example even.
It can be said in any of the four plus one tones, so there are five different meanings.

In languages with tone, an upward or downward tone are just as meaningful as two letters that change in voicing (often these languages, voicing differences matter less).

Some of those who explain Chinese even mentioned examples comparable to "paper vs. waiter". They are very clear to maybe almost any (non-beginner) English speaker. But we wouldn't always realize that tone changes have the very same effect.

[Daniel N.]

In (standard) Serbo-Croatian each stressed syllable is of the two types: rising or falling. When the pitch is falling, it stays low for the rest of the word. When it's rising, it continues to rise for one-two syllables (the exact pattern depends on the number of syllables after the stressed one) and then falls down afterwards.

This is an excellent explanation (I think I'll steal it) just one tiny detail: stress shifts or changes tone in various forms of one word. Famously, words like voda water have the rising stress in nominative, but falling in accusative (beside the change of ending!). Even better, putting a preposition before a noun (or negation before the verb) can affect the stress (which can move to preposition and sometimes also change pitch).

However, many dialects don't have this "move" feature. And many dialects (including the one of Zagreb, the capital of Croatia) have no pitch at all (and the stress is often on a different syllable than in standard). There are variations also in Serbia.

The end result is: if you have pitch stress in your home dialect, you use it; if you don't, you don't, so you can watch a TV show where one person asks a question with pitch stress, and another responds without any pitch. The stress is not indicated in writing, so everyone can spell the same. So in the long run, the pitch stress is probably going to become marginal one day, at least in Croatia.

[Random Review]

Apart from the obligatory Mandarin tone error (to be fair, they don't claim to speak it AFAIK), this is by far the most accessible explanation I've ever seen:

The video is actually about lexical tone and the section on pitch accent is just a few seconds long (blink and you'll miss it); but the wide ranging discussion of intonation, stress and lexical tone in the rest of the video help understand pitch accent better I think.