"Chopin and Beethoven" is plural so it must be "were", but "... my favourite by her performance" does not seem like correct English. Where did this sentence come from?

There are many pianists who play Chopin and Beethoven. But the one that I'm talking about is Alice(the pianist).

How can I interpretet this sentence so that the English is correctly?

"interpret" means understand what someone else has written, but it seems that you are actually trying to write the sentence yourself. If so, perhaps you mean this:

She was always my favourite performer of Beethoven and Chopin.

(Other people also play music by Beethoven and Chopin, but you like Alice's performances best.)

Thanx.

Can I write: are the 3sentences right?

1)Alice always plays my favourite music/ or Chopin.

2)It is so cool.

3)The concert will take place on the 8th of March 2015 in Frankfurt this time.

Kodachen11)Alice always plays my favourite music/ or Chopin.2)It is so cool.3)The concert will take place on the 8th of March 2015 in Frankfurt this time.

1) "Alice always plays my favourite music" is correct.

It is not clear exactly what you mean by "/ or Chopin".

2) "It is so cool" is OK in informal English. It is not suitable for formal si

So this time

Is that right?

Kodachen1So this timeIs that right?

It is right provided there is a reason for the word "So" (e.g. you are explaining a consequence of something else that you have just mentioned). Do not fall into the bad habit of starting sentences with an unnecessary "So".

Alice always plays my favourite music Chopin

Right?

Kodachen1Alice always plays my favourite music ChopinRight?

It needs some punctuation:

Alice always plays my favourite music: Chopin.
Alice always plays my favourite music — Chopin.