Simplify the following text for a Grade 8 native English-speaking person.
Original: `` Waltzing Matilda '' is Australia 's most widely known bush ballad , a country folk song , and has been referred to as `` the unofficial national anthem of Australia '' .
Simplified: `` Waltzing Matilda '' is one of Australia 's best known songs . The bush ballad , a country folk song , has been called `` the unofficial national anthem of Australia '' .