Perhaps you can quickly show Basquiat's and Keith Haring's work.
Then by all means you must have criteria for the graffiti...here would be
mine (6:20 in the am keep in mind, there might be ones I can't think of) a)
NO SEX/ALCOHOL/DRUGS IMAGERY OR REFERENCES and b)NO GANG IMAGERY OR
REFERENCES, and c) NO BAD REMARKS ABOUT STUDENTS, TEACHERS OR COMMUNITY. I
think that would cover it for me.