Learn Hardcore Russian: Концерт проходит на центральной площади. - The concert takes place in the central square.

Here проходит is an intransitive verb meaning “takes place” or “is being held”. It does not mean “walks” or “passes by” in this context. Instead, it indicates that the event (the concert) happens at a certain time and place.

Why is на центральной площади in the prepositional case?

The prepositional case (also called locative) is used after the preposition на to express location (“where?”). Since the concert takes place and is not moving toward the square, you describe its location with на + prepositional (площадь → площади́ → площади́ with stress shift, and центральная → центральнóй).

Why do we use на and not в before центральной площадью?

Russian distinguishes places like squares, markets and most public open areas with на. So you always say на площади, на рынке, на улице (“on the square,” “at the market,” “on the street”), even though in English you might use “in.”

Why does центральной end in -ой instead of -ая?

Adjectives agree in gender, number and case with the noun. Here площадь is feminine singular, and because it’s in the prepositional case, the typical ending for feminine adjectives is -ой (центральная → центрально́й).

Could you say Концерт идёт на центральной площади instead?

Yes. Using идёт (“goes,” colloquially “is happening”) is quite common:
“Концерт идёт на центральной площади.”
It has roughly the same meaning, though проходит sounds slightly more formal or neutral.

Can проходит be replaced with проводится here?

Absolutely. Проводится is the passive impersonal form of проводить and also means “is being held”:
“Концерт проводится на центральной площади.”
This version is a bit more formal or official.

What is the difference between площадь and площадка?

площадь: a town square or plaza, usually large and open.
площадка: a smaller platform, site, playground or stage area.
They share the same root but refer to different types of spaces.

Where is the stress in центральной and площади?

центральной: stress on the о́ (центральнóй).
площади: stress on the а́ (площáди).

How do you pronounce the soft sign in площадь?

The soft sign ь doesn’t have a sound of its own but makes the preceding consonant д soft (palatalized). So д sounds like [dʲ], not the hard [d]. You’ll hear something like plosh-chad’ with a slight “y”-glide on the д.