Context is everything: distinguishing between the three types of sources (primary, secondary and tertiary) will vary according to context and situation. For example, if you are analyzing how African American history was depicted in middle school textbooks in the 1980s, then the textbooks would be considered a primary source rather than a tertiary one.
|Art||creative artifacts: drawings, paintings, sculpture etc.|
|Music||sheet music, recordings|
|English||play, poem or novel|
|Political Science||treaties, congressional record|
|Sciences||report/article documenting an original experiment/study|
|Film/Television||script, video recording, film|
Some of this content adapted from: http://www.lib.vt.edu/help/research/primary-secondary-tertiary.html