Le due voci armonizzano bene.

Le is the feminine plural definite article, meaning the.

It is used because voci (voices) is:

• feminine
• plural

So:

• la voce = the voice
• le voci = the voices

In Le due voci armonizzano bene, le due voci means the two voices.

Due does not change for gender. It stays the same with masculine and feminine nouns.

Examples:

• due ragazzi = two boys
• due ragazze = two girls
• due voci = two voices

So even though voci is feminine, due still remains due.

Because the sentence is talking about two voices, the noun has to be plural.

The singular is:

• voce = voice

The plural is:

• voci = voices

This is a normal plural pattern for many Italian nouns ending in -e:

• singular -e
• plural -i

So:

• la voce
• le voci

Armonizzano is the third person plural present indicative of armonizzare.

Infinitive:

• armonizzare = to harmonize

Present tense:

• io armonizzo = I harmonize
• tu armonizzi = you harmonize
• lui/lei armonizza = he/she harmonizes
• noi armonizziamo = we harmonize
• voi armonizzate = you all harmonize
• loro armonizzano = they harmonize

Here the subject is le due voci (the two voices), which is plural, so Italian uses armonizzano.

Italian usually does not need subject pronouns when the verb ending already shows who the subject is.

So instead of saying:

• Loro armonizzano bene

Italian normally just says:

• Armonizzano bene

In this sentence, the subject is explicitly stated as Le due voci, so adding loro would usually be unnecessary unless you wanted emphasis.

Bene means well here.

It is an adverb modifying the verb armonizzano:

• armonizzano bene = harmonize well

This is similar to:

• cantano bene = they sing well
• stanno bene insieme = they go well together

So bene describes how the voices harmonize.

Because bene is an adverb, while buone is an adjective.

In this sentence, we are describing the action:

• They harmonize well

So Italian uses the adverb:

• bene

If you used buone, you would be describing the noun voci directly:

• buone voci = good voices

Compare:

• Le due voci armonizzano bene. = The two voices harmonize well.
• Le due voci sono buone. = The two voices are good.

Armonizzare is a perfectly normal verb, and it is especially common in musical contexts.

In a sentence like this, it most naturally refers to voices that blend or work well together musically:

• Le due voci armonizzano bene.

It can also be used more broadly in figurative contexts, where things go well together or are in harmony.

So the sentence most likely has a musical sense, but the verb itself is not limited only to music.

You may encounter reflexive-style uses like si armonizzano, but in this sentence armonizzano bene is the most straightforward and natural way to say that the two voices harmonize well.

Using si can sound more like:

• they harmonize with each other
• they become harmonized / fit together

But for a learner, the safest pattern here is:

• Le due voci armonizzano bene.

That is clear, idiomatic, and easy to understand.

This is the standard Italian order:

subject + verb + adverb

So:

• Le due voci = subject
• armonizzano = verb
• bene = adverb

Italian word order is fairly flexible, but this version is the most neutral and natural.

You might also hear:

• Le due voci bene armonizzano — possible in poetry or marked style, but not the normal everyday order
• Armonizzano bene, le due voci — possible if the speaker wants to emphasize the result first

For ordinary usage, Le due voci armonizzano bene is the best standard form.

It means the two voices.

The article le makes the phrase definite:

• le due voci = the two voices

If you said:

• Due voci armonizzano bene

that would mean Two voices harmonize well, which sounds more general or less specifically identified.

So the article tells us the speaker has a particular pair of voices in mind.

A careful pronunciation would be roughly:

leh DOO-eh VO-chee ar-mo-neet-TSA-no BEH-neh

A few useful notes:

• voci = VO-chee, not VO-see
• zz in armonizzano is pronounced like ts or tts
• bene has two clear syllables: BE-ne

In IPA, a standard pronunciation is approximately: /le ˈdu.e ˈvɔ.tʃi armoˈd͡d͡zaːno ˈbɛːne/

Most naturally, yes: it suggests two voices sound good together, especially in singing or vocal music.

However, depending on context, it could also be understood more broadly as:

• two tones blending well
• two speaking voices sounding pleasant together
• two elements being in harmony in a figurative sense

Still, if someone sees this sentence without any context, they will probably think first of singing voices.