Complex sentence: Joel accuses Denise of holding out on him with such a great song, she angrily reminds him that it was his own advice that resulted in the song in the first place and he argues back that he can't sell girl singers at this time.
Split into simpler sentences: Joel accuses Denise of holding out on him with such a great song, she angrily reminds him that it was his own advice that resulted in the song in the first place. He argues back that he can't sell girl singers at this time.