This music is usually related to the deep southerns. It can be refered to "twangy" because of the banjos and other musical instruments. It is similar to country music but bluegrass usually are based upon religion, freedom, and the older days. Some songs are the artist just talking/singing or they have several musical instruments such as a banjo, violin, and more banjos. The songs almost never have a negative message and are created for easy listening. Bluegrass is a genre of music that is REALLY hard to sing or play but sounds excellent when done correctly.
That concert by Ralph Stanley was like none other, that guy has the skills and talent to be considered number one.
What are you talking about, he IS a living legend for bluegrass music.