Fidicen ante vestibulum stat et brevem cantum modulatur.

Fidicen is a noun meaning a stringed-instrument player, often something like a lyre-player or harpist.

In this sentence, fidicen is:

• nominative singular
• the subject of both verbs, stat and modulatur

So fidicen is the person who is standing and performing the song.

It is the subject because it is in the nominative case, which is the case normally used for the subject of a sentence in Latin.

Here the structure is:

• fidicen = the musician
• stat = stands
• modulatur = sings/plays/modulates

So the sentence is saying that the musician does both actions.

Ante vestibulum means in front of the entrance or before the doorway/forecourt.

A few details:

• ante is a preposition meaning before or in front of
• vestibulum can mean an entrance area, doorway, vestibule, or forecourt

In this sentence, it tells you where the musician is standing.

Because ante is a preposition that takes the accusative case.

So:

• ante + accusative = before / in front of
• vestibulum here is the accusative singular form

Even though in English location is often shown with in or at, Latin often uses a preposition plus a specific case ending.

Because stat means specifically stands, not just is.

Latin often prefers a more vivid verb when describing position:

• est = is
• stat = stands

So fidicen ante vestibulum stat does not merely mean the musician exists there; it gives the picture of him standing there.

Brevem cantum is the direct object of modulatur.

It means a short song or a brief tune.

Both words are in the accusative singular:

• brevem = short
• cantum = song, chant, tune

So the musician is performing a short song.

Because brevem has to agree with cantum.

Agreement means that an adjective must match its noun in:

• gender
• number
• case

Here:

• cantum is masculine accusative singular
• so brevis must also become masculine accusative singular
• that form is brevem

So:

• brevis cantus = a short song (subject form / nominative)
• brevem cantum = a short song (object form / accusative)

Because it is the direct object of modulatur.

The verb modulatur here means something like:

• performs
• sings
• plays
• modulates

The thing being performed is cantum, so Latin puts it in the accusative case.

Because modulatur comes from a deponent verb.

A deponent verb:

• has passive forms
• but an active meaning

So although modulatur looks passive, it means something active, like:

• he performs
• he sings
• he plays melodically

This is very common in Latin, and learners often need time to get used to it.

Modulatur is:

• 3rd person singular
• present tense
• indicative mood
• from the deponent verb modulor, modulari

So it means he/she performs/sings/plays.

Because the subject is fidicen, we understand it here as the musician performs.

Because Classical Latin does not have articles like English the and a/an.

So fidicen can mean:

• a musician
• the musician

and brevem cantum can mean:

• a short song
• the short song

You decide from the context which English wording is best.

Et simply means and.

It joins the two verbs:

• stat
• modulatur

Both verbs share the same subject, fidicen.

So the structure is:

• The musician stands
• and
• (the musician) performs a short song

Latin often leaves the subject unstated with the second verb when it is the same as the first.

The word order is natural, but Latin word order is more flexible than English because the endings show each word’s role.

Here we get:

• fidicen = subject
• ante vestibulum = place
• stat = first action
• et = and
• brevem cantum = object
• modulatur = second action

A rough pattern is: subject + place + verb + and + object + verb

Latin could rearrange many of these words without changing the basic meaning, though the emphasis or style might change.