Der Headliner ist beim Soundcheck.

Because Headliner is a noun, and every German noun has a grammatical gender. Headliner is normally treated as masculine, so its nominative singular article is der.

• der Headliner = the headliner

This does not necessarily mean the person is male in real life; it is mainly about the noun’s grammatical gender. In practice, though, der Headliner is the standard general form.

It is an English loanword that German uses, especially in music, festivals, and entertainment. German often keeps English-looking words in these contexts.

So Headliner in German means basically the same thing as in English: the main act or top-billed performer.

Ist is the 3rd person singular form of sein = to be.

The subject is der Headliner, which is singular, so German uses:

• ich bin
• du bist
• er/sie/es ist

So:

• Der Headliner ist ... = The headliner is ...

Beim is a very common contraction of bei dem.

• bei = at, with, near, during (depending on context)
• dem = the, in the dative masculine/neuter singular

So:

• beim = bei dem

In this sentence, beim Soundcheck means something like:

• at the soundcheck
• sometimes during the soundcheck, depending on context

Because bei always takes the dative case.

The noun Soundcheck is masculine: der Soundcheck.
When a masculine noun is in the dative singular, der changes to dem:

• nominative: der Soundcheck
• dative: dem Soundcheck

And bei dem usually contracts to beim:

• bei dem Soundcheck → beim Soundcheck

Der Headliner is in the nominative case because it is the subject of the sentence — the person doing the being in ist.

A quick breakdown:

• Der Headliner = subject, nominative
• ist = verb
• beim Soundcheck = prepositional phrase with dative

It can suggest either, depending on context.

Most naturally, it means:

• at the soundcheck = the headliner is there

But it can also have a slightly temporal sense:

• during the soundcheck

This is normal with bei in German. It often covers both the idea of being at an event and being in the course of that event.

Because in German, all nouns are capitalized.

So even though these are loanwords from English, once they function as nouns in German, they are capitalized:

• der Headliner
• der Soundcheck

This is one of the most noticeable spelling rules in German.

Yes. German word order is flexible, but the conjugated verb usually stays in the second position in a main clause.

For example, these are both correct:

• Der Headliner ist beim Soundcheck.
• Beim Soundcheck ist der Headliner.

The second version emphasizes beim Soundcheck more.
Notice that ist still remains in second position.

Beim is pronounced roughly like bime in English.

A simple approximation:

• bei sounds like English bye
• beim sounds like bym or bime

So:

• beim Soundcheck ≈ bime ZOWNT-chek

That is only an approximation, but it is close enough for a learner.

Yes, that is grammatically correct, because beim is just the contraction of bei dem.

So these mean the same thing:

• Der Headliner ist beim Soundcheck.
• Der Headliner ist bei dem Soundcheck.

But in normal everyday German, beim sounds much more natural.

It follows a very common German pattern:

• Subject + verb + prepositional phrase

So here:

• Der Headliner = subject
• ist = verb
• beim Soundcheck = prepositional phrase

This is a very useful model for beginners, because many simple German sentences work the same way.