For one tired out from work, autumn is one of the best times to step into the open air to _ and enjoy some great music. And that's what many Beijingers have done this past weekend. Family, friends, laughter; beautiful grass, fresh air and live music echoing   off the forest and the Great Wall that surround this place. A weekend in this music paradise  just seems too short. Besides, a brand new world-class outdoor theater has just been open at this year's festival, which will surely make the festival a better and more permanent experience. A full house is before the new outdoor amphitheater  . Even the thunderstorm couldn't break up the crowd completely absorbed in the music. Thanks to the new theater, this year's Great Wall Forest Festival offers even more superb acoustics and an overall outdoor theatrical experience, even though the project is still half complete. The festival is now in its fourth year. Since its first show in 2010, the festival has seen a steady increase in festival-goers and has expanded its length from two days to four days, divided over two weekends. It has also been experimenting with a variety of styles, from classical to pop, with this year's theme "Celebrating 20 Years of Chinese Folk Song." Folk Song legend Lao Lang explains how folk songs have helped encourage more amateur folks to express themselves through music. "Before music was reserved for the professionals. But folk songs made young people realize that they can express themselves through music as well. And that's what characterizes folk songs. It's popular music and it always has a story." said Lao Lang. Unlike some of the other outdoor festivals, the Great Wall Forest Festival appeals to a wide range of audiences. It's a rare place where teens, parents and families can all enjoy the outdoors and have a great time. Great music and scenery aside, many children's workshops, master music classes, and interactive art activities have also been introduced this year. If music is the reason to come to the festivals, you'll find even more reasons not to leave. The 2014 Great Wall Forest Festival has got improved in the following aspects except that   _  .
it has included different types of music it has attracted a wide range of audiences it has introduced more activities besides music it has been expanded from 2 days to 4 days in a week