Can I incorporate a third-party work (such as a musical composition, sound recording, or image), without permission, as long as I modify it sufficiently?

If you incorporate any copyrightable element that is “substantially similar” to part of another creator’s work, you must have permission from the copyright owner to incorporate that element. For example if you wanted to use a beat from another song, you should seek permission to use it, even if you change the beat by slowing it down, speeding it up or changing the pitch. Otherwise, you may still be violating the copyright owner’s exclusive right to create a derivative work.