Concerts involving a greater number of artists, especially those that last for days, are known as festivals. Unlike other concerts, which typically remain in a single genre of music or work of a particular artist, festivals often cover a broad scope of music and arts. Due to their size, festivals are almost always held outdoors. A few examples of the hundreds of festivals include: Bayreuth Festival, Big Day Out, Coachella, Falls Festival, Glastonbury Festival, Mostly Mozart Festival, Newport Jazz Festival, Oxegen, Parachute Music Festival, Rock In Rio, Rockwave Festival, Salzburg Festival, Summer Sonic Festival, Tanglewood Music Festival, Woodstock Music and Art Festival, the Warped Tour, or the Umbria Jazz Festival.