The First Amendment to the United States Constitution
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

Website http://law2.umkc.edu/faculty/projects/ftrials/conlaw/studentspeech.htm
Hypothetical Band Tee Shirt Video 1 http://law2.umkc.edu/faculty/projects/ftrials/conlaw/studentspeech.htm
Video (Schools Side) Freedom of Speech 2 ( Tinker ) http://vimeo.com/66817013
Video (National History Day Project) Freedom of Speech 3 ( Tinker ) https://www.youtube.com/watch?v=wzF8MxX5RbQ
Video Lego Informational Freedom of Speech Tinker 4 https://www.youtube.com/watch?v=
According to some Supreme Court Cases
Freedom of speech includes the right:
Not to speak (specifically, the right not to salute the flag).
West Virginia Board of Education v. Barnette, 319 U.S. 624 (1943).
Of students to wear black armbands to school to protest a war (“Students do not shed their constitutional rights at the schoolhouse gate.”).
Tinker v. Des Moines, 393 U.S. 503 (1969).
To use certain offensive words and phrases to convey political messages.
Cohen v. California, 403 U.S. 15 (1971).
To contribute money (under certain circumstances) to political campaigns.
Buckley v. Valeo, 424 U.S. 1 (1976).
To advertise commercial products and professional services (with some restrictions).
Virginia Board of Pharmacy v. Virginia Consumer Council, 425 U.S. 748 (1976); Bates v. State Bar of Arizona, 433 U.S. 350 (1977).
To engage in symbolic speech, (e.g., burning the flag in protest).
Texas v. Johnson, 491 U.S. 397 (1989); United States v. Eichman, 496 U.S. 310 (1990).
Freedom of speech does not include the right:
To incite actions that would harm others (e.g., “[S]hout[ing] ‘fire’ in a crowded theater.”).
Schenck v. United States, 249 U.S. 47 (1919).
To make or distribute obscene materials.
Roth v. United States, 354 U.S. 476 (1957).
To burn draft cards as an anti-war protest.
United States v. O’Brien, 391 U.S. 367 (1968).
To permit students to print articles in a school newspaper over the objections of the school administration.
Hazelwood School District v. Kuhlmeier, 484 U.S. 260 (1988).
Of students to make an obscene speech at a school-sponsored event.
Bethel School District #43 v. Fraser, 478 U.S. 675 (1986).
Of students to advocate illegal drug use at a school-sponsored event.
Morse v. Frederick, __ U.S. __ (2007).
Linked Articles
Web site Free speech and public schools - http://www.centerforpubliceducation.org/Main-Menu/Public-education/The-law-and-its-influence-on-public-school-districts-An-overview/Free-speech-and-public-schools.html
Student's Free Speech Rights and the Internet http://www.edu-cyberpg.com/Teachers/studentfreespeach.html