singular or plural

Some context?

no....

just would like to know:
some concerts/ or some concert?

I wish someday you could make concerts also in Europe.

is you could a formal writing? is the sentence right?

?

Also would tend to go before the verb:

I wish someday you could also make concerts in Europe.

or after the entire object:

I wish someday you could make concerts in Europe also.

And you would probably describe the person's role if possible, rather than just say make:

I wish someday you coul

In the right context, it can be used with a singular noun.

Where's Joan?
I'm not sure. I think she had tickets for some concert.

True! That would be definition 1 of some on the Learner's Dictionary—used to refer to a person or thing that is not known, named, or specified. Then it would depend on whether you meant one unknown concert, or more than one.

The other examples would be definition 2a—of