Marcus Weeks was a contributing writer for The Philosophy Book, The Psychology Book, The Economics Book, The Politics Book, and The Religions Book for DK. He has written many other books, including but not limited to Mozart: The Boy Who Changed the World With His Music (National Geographic, 2007); Music: A Crash Course (Simon & Schuster, 1999); and How Many Elephants in a Blue Whale? (Barnes & Noble, 2010). His hobbies and interests include writing palindromic poetry, compiling and solving cryptic crossword puzzles, and playing the trombone in jazz and ska/funk bands.