Art can be a separate subject- learning about lines, colors, textures, studying artists, etc. But, art has a role in every subject. There is a way to integrate art into every subject. This not only spikes interest, but also helps the students to understand and remember the concepts better. Here are some lessons that I plan to use at some point with my children (I homeschool) that integrate the arts into other subject areas.
Geometry-constructing a bridge lesson plan
http://www.scholastic.com/browse/lessonplan.jsp?id=1509
Pizza Fractions
http://4thgradefrolics.blogspot.com/2015/03/pizza-fractions-project.htmlSocial Studies Biography Project
https://drive.google.com/file/d/0B1xZ3z7a2i6lY3dEc044NUd1Zm8/viewPlanets Lesson with art project and song
http://littlepriorities.blogspot.com/2012/04/space-adventure.html