The state also has a unique rural-urban dynamic, which has influenced the development of local bluegrass, folk, and alternative country music. Jam bands have a strong presence in the state, dating back to Grateful Dead performances at the Oregon Country Fair, and outdoor music festivals continue to be popular. Portland's Waterfront Blues Festival is the second largest blues festival in the country. Prominent cultural institutions include the Oregon Bach Festival, Oregon Festival of American Music, Oregon Symphony, and Mt. Hood Jazz Festival.