Not a lawyer, but... Yes. At least in the U.S. http://www.copyright.gov/help/faq/faq-fairuse.html#change http://www.copyright.gov/help/faq/faq-fairuse.html#cha

Not a lawyer, but... Yes. At least in the U.S. http://www.copyright.gov/help/faq/faq-fairuse.html#change http://www.copyright.gov/help/faq/faq-fairuse.html#change See also the previous question on that page, called "How much of someone else's work can I use without getting permission?"