sabi wo mou itido utaou.

In music, サビ means the chorus or hook of a song—the catchy repeated part.

It is written in katakana because it is treated like a music term in modern Japanese.

を marks the direct object of the verb.

Here, the verb is 歌おう from 歌う = to sing, so サビを means the chorus as the thing being sung.

So the structure is basically:

サビを = the chorus
歌おう = let’s sing

Together: Let’s sing the chorus.

Here, もう means another or again.

When it combines with 一度, the phrase もう一度 means:

• once more
• one more time
• again

So もう adds the idea of repeating something.

一度 literally means one time or once.

By itself, it can mean once. In this sentence, it appears in the common phrase もう一度, which means one more time.

So:

• 一度 = once
• もう一度 = once more / one more time

歌おう is the volitional form of 歌う.

The volitional form is often used to mean:

• let’s sing
• we’ll sing
• I’ll sing

In this sentence, the natural meaning is let’s sing.

So:

• 歌う = to sing
• 歌おう = let’s sing

歌う is a u-verb.

To make the volitional form of a u-verb, change the final u sound to the o row and add う.

So:

• 歌う → 歌おう

More examples:

• 行く → 行こう = let’s go
• 読む → 読もう = let’s read
• 話す → 話そう = let’s talk

Yes. 歌おう is a casual way to say let’s sing.

A more polite version would be:

サビをもう一度歌いましょう。

That would sound more polite or formal.

So the difference is roughly:

• 歌おう = casual / plain
• 歌いましょう = polite

Grammatically, the volitional form can sometimes express the speaker’s intention: I’ll sing.

However, in a sentence like this, especially without more context, the most natural interpretation is usually an invitation or suggestion:

Let’s sing the chorus one more time.

Context decides which meaning is intended, but let’s sing is the safest reading here.

もう一度 is an adverbial expression telling you how often the action happens: one more time.

It modifies the verb 歌おう.

Japanese adverb-like expressions often come before the verb, so:

サビを もう一度 歌おう

literally feels like:

the chorus, one more time, let’s sing

That is normal Japanese word order.

Yes, sometimes.

For example:

• サビをもう一度歌おう。
• もう一度サビを歌おう。

Both are natural and mean basically the same thing.

Japanese word order is more flexible than English, as long as the particles make the roles clear.

Yes. もう一回 also means one more time.

So this would also work:

サビをもう一回歌おう。

The difference is mainly nuance:

• もう一度 = slightly more neutral / a bit more formal
• もう一回 = more casual and conversational

In everyday speech, both are very common.

No. Japanese is normally written without spaces.

So the standard writing would be:

サビをもう一度歌おう。

The spaced version is often used only for learners, to make it easier to read.

It is pronounced roughly as:

sabi o mou ichido utaou

A natural rhythm would be:

sa-bi o mo-u i-chi-do u-ta-o-u

A few notes:

• サビ = sabi
• を is pronounced o
• もう has a long o sound
• 歌おう also has a long ending: utaō

So it sounds something like:

sabi o mō ichido utaō