Escucha el compás musical; si no, lo perderás.

Yes. Escucha is the affirmative tú command of escuchar.

• escuchar = to listen
• (tú) escucha = listen

So the sentence is telling someone directly: Listen to the musical beat...

A useful thing to remember is that for many verbs, the affirmative tú command looks the same as the él/ella/usted form of the present tense:

• tú escuchas = you listen
• él/ella escucha = he/she listens
• escucha = listen! (command to tú)

So here it is not he/she listens; it is clearly a command from context.

Because escuchas is the normal present tense form for you listen, while escucha is the command form.

Compare:

• Escuchas el compás musical. = You listen to the musical beat.
• Escucha el compás musical. = Listen to the musical beat.

In this sentence, the speaker is giving advice or an instruction, so the command form is needed.

Here, compás refers to the beat, rhythm, or meter in music.

Depending on context, compás can mean things like:

• beat
• rhythmic pattern
• musical meter
• sometimes even bar/measure

In this sentence, the idea is that you should keep track of the rhythm so that you do not lose it.

Yes, often compás by itself already suggests a musical meaning, so musical can feel a bit explicit or slightly redundant.

• Escucha el compás would often be enough.
• Escucha el compás musical adds clarity and emphasizes that we are talking about the musical beat, not some other meaning of compás.

So it is understandable, but in many natural contexts a native speaker might simply say:

• Escucha el compás; si no, lo perderás.

Spanish often uses the definite article more than English does.

Here, el compás musical means something like:

• the beat
• the rhythm
• the musical meter

It refers to the specific beat of the music being discussed or heard.

English might sometimes just say Listen to the beat, and Spanish naturally does the same with el:

• Escucha el compás.

Using no article here would generally sound wrong.

Because si no and sino are different things.

si no = if not / otherwise

That is what we have here:

• Escucha el compás musical; si no, lo perderás.
• Listen to the beat; otherwise, you will lose it.

sino = but rather / but instead

This is used to correct or contrast something:

• No es fácil, sino difícil.
• It’s not easy, but rather difficult.

So in your sentence, it must be si no because it introduces a consequence: if you don’t, you’ll lose it.

Because si without an accent means if.

Compare:

• si = if
• sí = yes

So here:

• si no = if not / otherwise

Not:

• sí no, which would not make sense here.

Lo is a direct object pronoun meaning it.

It refers back to el compás musical.

• el compás is masculine singular
• so the pronoun is lo

So:

• lo perderás = you will lose it

This is a very common Spanish pattern: instead of repeating the noun, Spanish uses an object pronoun.

Compare:

• Escucha el compás. Perderás el compás.
• more naturally: Escucha el compás. Lo perderás.

Because it refers to el compás, which is a masculine singular noun.

Spanish object pronouns agree with the noun they replace:

• el compás → lo
• la música → la
• los compases → los
• las notas → las

So lo perderás is correct because compás is masculine singular.

Yes. Perderás is the future tense of perder for tú:

• perder = to lose
• perderás = you will lose

In this sentence, the future tense expresses the likely consequence of not following the instruction:

• Escucha el compás musical; si no, lo perderás.
• Listen to the beat; otherwise, you’ll lose it.

This is very natural in Spanish for warnings, predictions, or expected results.

Yes, depending on style and tone.

For example:

• ...si no, lo vas a perder. = ...otherwise, you’re going to lose it.
• ...si no, pierdes el compás. = ...otherwise, you lose the beat.

But lo perderás sounds concise and clear, and it works well as a warning or instruction.

Because escuchar usually takes a direct object.

So you say:

• Escucha la música.
• Escucha el compás.
• Escucha la canción.

With people, Spanish often uses the personal a:

• Escucha a tu profesor. = Listen to your teacher.

But with things like music, beat, or sound, you normally do not use a.

That is why Escucha el compás is correct.

Yes. Perder el compás is a natural expression meaning to lose the beat or to fall out of rhythm.

It can be used literally in music or dance:

• El bailarín perdió el compás.
• The dancer lost the beat.

So in your sentence, lo perderás is referring to that same idea: you will lose the rhythm/beat if you do not pay attention.

The semicolon links two closely related parts:

1. Escucha el compás musical
2. si no, lo perderás

It works a bit like a strong comma or a softer full stop. It signals:

• first, the instruction
• then, the consequence

You could also see versions with a comma or full stop depending on style:

• Escucha el compás musical, si no, lo perderás.
• Escucha el compás musical. Si no, lo perderás.

The semicolon is just a neat way to connect the two closely related ideas.

Compás is stressed on the last syllable:

• com-PÁS

The written accent mark shows that stress clearly.

Without getting too technical, the accent is there because the word ends in -s but the stress falls on the final syllable, which needs to be marked in Spanish spelling.

The same happens in perderás:

• per-de-RÁS

That accent also marks the stress.

Yes, the sentence is understandable and grammatically correct. A native speaker would understand it easily.

That said, in many real situations, a speaker might say something slightly simpler and more idiomatic, such as:

• Escucha el compás; si no, lo perderás.
• Sigue el compás; si no, lo perderás.
• Presta atención al compás; si no, lo perderás.

Compás musical is not wrong, but compás alone is often enough if the musical context is already obvious.