How can these sentences be combined to include a dependent clause? the pianist had great talent. he could play rachmaninoff blindfolded.

The given sentences on the question are following:

1.The pianist had great talent.

2.He could play Rachmaninoff blindfolded

These two sentences can be combined including a dependent clause.So, the answer of the question is given below.

*The pianist had a great talent who play Rachmaninoff blindfolded.

Explanation:The dependent clause are the kind of clause those who  can not express a meaningful sentence without the help of other clause. They normally start with a subordinate conjunction.  There are three kinds of dependent clause. They are:1. Adjective clause

                                                                 2.Adverbial clause

                                                                  3. Noun clause.

The sentence combined on our answer is a noun clause.

By the way you put the answer in your question you put:

It helps the reader understand why Stanley and his family always have bad luck. It helps the reader to understand why Stanley was sent to Camp Green Lake. It makes the story less interesting and more difficult for the reader to follow. It makes the story more predictable and easier for the reader to understand.

Which is your answer