Thành viên hợp xướng hát lạc nhịp.

Vietnamese usually follows a straightforward Subject + Verb + Complement pattern.

Here:

• Thành viên hợp xướng = the subject
• hát = the verb
• lạc nhịp = the result/state of the singing, meaning off the beat / out of rhythm

So the sentence is structured as:

[choir member] + [sings] + [off-beat]

That is very normal in Vietnamese.

Yes, word-for-word it is something like:

• thành viên = member
• hợp xướng = choir / choral singing

Together, thành viên hợp xướng means choir member.

Vietnamese often places nouns next to each other without extra words like of. So instead of saying member of the choir, Vietnamese can simply say thành viên hợp xướng.

A slightly fuller version would be:

• thành viên của dàn hợp xướng
• thành viên trong dàn hợp xướng

Both mean a member of the choir.

Hợp xướng refers to choral singing or a choir.

Depending on context, it can mean:

• the musical style: choral music / choral singing
• the group itself: choir

So in this sentence, thành viên hợp xướng is understood as a choir member.

You may also see related expressions such as:

• dàn hợp xướng = choir, chorus
• ban hợp xướng = choir group

Literally:

• lạc = to lose, go astray, be off
• nhịp = beat, rhythm, tempo

So lạc nhịp literally means to lose the beat or to go off the rhythm.

In natural English, it often becomes:

• off-beat
• out of rhythm
• out of time

In this sentence, hát lạc nhịp means to sing off the beat / out of time.

Because lạc nhịp describes how the singing happens or what state it ends up in.

So:

• hát hay = sing well
• hát to = sing loudly
• hát sai = sing incorrectly
• hát lạc nhịp = sing off-beat

Vietnamese commonly puts this kind of description after the verb.

Vietnamese nouns usually do not show singular/plural automatically.

So thành viên hợp xướng by itself is neutral and often understood from context. Depending on the situation, it could refer to:

• a choir member
• the choir member
• sometimes more generally choir members, though singular is more likely here

If you want to make it clearly singular, you could say:

• Một thành viên hợp xướng hát lạc nhịp. = A choir member sang/is singing off-beat.

If you want to make it clearly plural:

• Các thành viên hợp xướng hát lạc nhịp. = The choir members sing/are singing off-beat.

Vietnamese does not require articles like a/an/the the way English does, and it does not inflect verbs for tense.

So:

• hát can mean sing, sings, is singing, sang, depending on context
• thành viên can mean a member, the member, or just member

Time is usually shown by context or by extra words such as:

• đã = past
• đang = ongoing
• sẽ = future

Examples:

• Thành viên hợp xướng đã hát lạc nhịp. = The choir member sang off-beat.
• Thành viên hợp xướng đang hát lạc nhịp. = The choir member is singing off-beat.
• Thành viên hợp xướng sẽ hát lạc nhịp. = The choir member will sing off-beat.

Yes, it is understandable and grammatically fine. But depending on context, some speakers might prefer a slightly fuller phrase, especially if they want to sound more natural or specific.

Possible alternatives:

• Một thành viên trong dàn hợp xướng hát lạc nhịp.
• Một thành viên của dàn hợp xướng hát lạc nhịp.

These feel a little more explicit, like A member of the choir sang off-beat.

The original sentence is still perfectly understandable, especially in a textbook or example-sentence style.

Mostly, it is strongly associated with rhythm, timing, and coordination, especially in music or movement.

It can be used for:

• singing off the beat
• clapping out of rhythm
• dancing out of sync

For example:

• vỗ tay lạc nhịp = clap out of rhythm
• nhảy lạc nhịp = dance out of sync

So while it is not limited only to singing, it is definitely tied to the idea of rhythm/beat.

A rough guide:

• Thành — rising tone on a
• viên — level tone
• hợp — low, clipped/heavy tone
• xướng — rising-broken tone in the North
• hát — sharp rising tone
• lạc — low, clipped/heavy tone
• nhịp — low, clipped/heavy tone

A learner should especially pay attention to:

• hát vs similar-looking syllables without the same tone
• hợp, lạc, nhịp because the final -p/-c and heavy tone make them short and abrupt

If your tones are unclear, the sentence may still be understood from context, but these words sound much more natural when the tones are correct.

You could, but the meaning changes slightly.

• thành viên hợp xướng = choir member
• ca sĩ hợp xướng = choral singer / choir singer

Ca sĩ means singer, so it emphasizes the person as a singer.
Thành viên emphasizes membership in the group.

In many contexts both are possible, but thành viên hợp xướng fits best if you specifically mean a member of the choir.