Acoustic: genre or movement?

Acoustic music was actually born out of the introduction of electric instruments into the music world. It basically means that the music is born out of the "pure" instruments with no electronic enhancements. Top artists include: Matt Costa, Peter Bradley Adams, Dispatch, Lifehouse, Paramore, and many more. This does not mean that these and other artists do not use any electric devices. In fact, many (if not all) use electronic amplifiers in their performances; to purify their sound and distinguish it from that of electronic nstruments many artists place a microphone in front of their instrument and have that device wired into an amplifier. Acoustic artists tend not to solely play in this style of music; many of these musicians split their talents between what is now commonly referred to as "unplugged" (a term coined in the '90s) and utilizing all musical instruments to perform.
Lifehouse: Broken
Margot & the Nuclear So and So's

Fun Fact: One of a lesser known acoustic artists has become known more for his acting in a blockbuster movie series known as The Twilight Saga. Robert Pattinson, best known for playing Edward in the vampire movies is also an accomplished talent that has mastered the piano & guitar. He does not seek to promote his music but did have two of his original songs placed into the first Twilight movie. His haunting lyrics take one inside the emotion behind the music. The links below are to the songs featured in the movie.

Rob Pattinson, Let Me Sign
Rob Pattinson, Never Think

More information re: Bluegrass Music

One will always have access to the founding fathers & mothers of bluegrass music. In fact, in today's technological era there is an unprecedented ability to listen to artists that have been gone for years. Something that people often associate with bluegrass music is that it's "old-fashioned" or the music of their grandparents. People may not always associate this style of music with today's musicians or even as a growing genre with interest spanning the ages of students and musicians.
On the campus of East Tennessee State University this is a foreign concept. Bluegrass is not only a modern way of musical expression but one that is so popular that it drives a new major field of study at the university. This, along with the Appalachian Studies field has brought scholars into the school in varying ages and backgrounds, longing to learn more about the roots of their beloved music, while others are simply searching for a welcoming platform in which to market their talents. These musicians spend countless hours outside of class in practice sessions and performing for local businesses and charity events.
In addition to the sub-culture that Bluegrass adds to the ETSU campus, it is also a thriving art outside of the educational arena. Popular bands today such as The Lonesome River Band,  and Steve Martin (yes THAT Steve Martin)  provide the unmistakable blending of guitar, banjo, mandolin, fiddle, and other unique instruments. One has to only take the time to appreciate the history and depth behind this ageless music.
Here's a little taste of what could be considered Steve Martin's 'hidden talent:'

http://www.youtube.com/watch?v=Gnr9xkJbfhY&feature=related