All 16 words, sorted alphabetically. Group them into four categories of four.
The four category names, easiest to hardest. No words revealed yet.
Theme name plus one word from each category.
GRAFFITI, MURAL, POSTER, and STENCIL are all forms of visual art or imagery commonly found displayed on walls and surfaces in urban environments
HUSTLE, MASHED POTATO, ROBOT, and TWIST are all popular dance styles or crazes from past decades, each associated with a specific era of pop culture
CORPS, COUP, PSYCHO, and RECEIPT all contain a silent 'P' that is written but not pronounced when the word is spoken aloud
BEAUTY, CHECK, QUESTION, and STRETCH can all precede the word MARK to form common compound words: beauty mark, checkmark, question mark, and stretch mark