Learn Romanian: Plouă, dar orchestra cântă pe stradă. - It is raining, but the orchestra is playing on the street.

In Romanian, the verb a cânta literally means "to sing", but it is also the standard verb used for playing music or a musical instrument. You cannot use a juca (to play), because that is strictly reserved for games, sports, and theatrical roles.

Where is the word for "it" in Plouă?

Romanian doesn't use a "dummy pronoun" like English does for weather expressions. Weather verbs stand completely on their own in the third-person singular, so plouă contains the entire meaning of "it is raining".

The translation says "on the street", so why is it just pe stradă instead of the definite form pe strada?

In Romanian, when a noun follows a simple preposition like pe, în, or la to indicate a general location, the definite article is usually dropped. You would only use the definite form strada if you were adding a specific modifier, like in pe strada principală (on the main street).

Why does orchestra look exactly like the English word, despite Romanian attaching "the" to the end of nouns?

It looks identical by coincidence, but the grammar is doing exactly that. The base Romanian noun is orchestră (ending with an ă). The -a you see at the end of orchestra in this sentence is the feminine definite article ("the"), which replaces the final ă.