Solist değişebilir, yeter ki deşifre için herkes hazır olsun.

It can mean any of those depending on context.

• değişmek = to change
• değişe-bil-ir = can/may/might change

Here, -ebil- is the potential marker, and -ir is the aorist ending. Together, they often express:

• possibility: might change
• ability: can change
• permission/acceptability in context: it’s okay if the soloist changes

In this sentence, because of yeter ki ..., the overall sense is close to:

The soloist can change / it’s fine if the soloist changes, as long as everyone is ready...

Because değişebilir comes from değişmek, which is usually intransitive: to change.

So:

• Solist değişebilir = The soloist can change / The soloist may change

If you wanted can be changed, Turkish would normally use değiştirilebilir:

• değiştirmek = to change something
• değiştirilebilir = can be changed

So the sentence is not saying someone changes the soloist; it says the soloist itself may vary.

yeter ki is a fixed expression meaning:

• as long as
• provided that
• so long as
• sometimes if only

In this sentence, it introduces the condition:

• Solist değişebilir, yeter ki ...
• The soloist can change, as long as ...

It is a very common structure in Turkish for stating that something is acceptable under a certain condition.

Because after yeter ki, Turkish often uses a form that expresses a desired or required situation rather than a plain factual statement.

Here:

• olmak = to be
• olsun = roughly let it be / be

So:

• herkes hazır olsun = everyone be ready

This does not sound unnatural in Turkish. After yeter ki, this kind of form is very common because the speaker is expressing a condition that should be met.

So the structure is basically:

• yeter ki + [desired condition]

Example:

• Yeter ki gelsin. = As long as he/she comes.
• Yeter ki hazır olsunlar. = As long as they are ready.

Because herkes means everyone, and in Turkish it is grammatically treated as singular.

So Turkish uses a singular verb:

• herkes hazır olsun = let everyone be ready

Not:

• herkes hazır olsunlar

This is different from how English meaning feels, because everyone refers to multiple people, but grammatically it still behaves like a singular subject in both English and Turkish.

için means for.

So:

• deşifre için = for deşifre

The important part is what deşifre means in this context. In general Turkish, deşifre can mean deciphering or figuring something out. But in a music context, it often means sight-reading.

So here, deşifre için most likely means:

• for sight-reading
• for the sight-reading session

That fits well with the musical word solist.

No. hazır is an adjective meaning ready.

The verb is olsun from olmak (to be / become).

So the structure is:

• hazır = ready
• hazır olsun = be ready

Literally, it is something like let everyone be ready.

Because Turkish normally puts the verb at the end, and other elements can move around before it depending on emphasis.

This part is:

• deşifre için = for sight-reading
• herkes = everyone
• hazır = ready
• olsun = be

So literally:

• for sight-reading everyone ready be

Natural Turkish often works this way. The most important finite verb commonly comes last.

It can mean either one. Turkish has no definite or indefinite article like the or a/an in this kind of sentence.

So solist can mean:

• the soloist
• a soloist

The context decides which is more natural. In many real situations, English translation would use the soloist because the speaker probably has a specific performance or group in mind.

It sounds like the speaker is being flexible about one thing, but firm about the condition.

So the tone is roughly:

• The soloist can change, that’s not the important part.
• What matters is that everyone is ready for the sight-reading.

The structure X değişebilir, yeter ki Y olsun is a very natural way in Turkish to say:

• X can vary/change, as long as Y is true.

It emphasizes the condition in Y as the real priority.