Complex sentence: He started to take stock of the importance of the people in his life and felt a need to say something about it, writing the song to deal with his problems of focusing on life by expanding his scope to include death and what comes afterward.
Split into simpler sentences: He started to take stock of the importance of the people in his life and felt a need to say something about it. He wrote the song to deal with his problems of focusing on life by expanding his scope to include death and what comes afterward.