Over the years, bluegrass music has spread from being a strictly American genre of roots music and country music to a standalone musical style. Emerging from Appalachia, in particular Kentucky, bluegrass bands use elements of Scottish, Welsh and English folk music. Unlike traditional old time music, each instrument plays a role in driving a song's melody while the other parts involve jamming around it. Bluegrass artists are also known for breakdowns where the tempo speed up, the chords are more challenging and thus, becomes a glorified jam session. Bluegrass bands first emerged in the 18th century, but bluegrass music as we know it today (that incorporates country western) first became relevant post-World War II.
So, who are the best bluegrass bands? Any list of bluegrass artists has to include names of famous male and female bluegrass singers, including Doc Watson, Bill Monroe, Alison Krauss & Union Station, Old Crow Medicine Show, Nickel Creek, and the Stanley Brothers. These are some of the best bluegrass bands and with good reason - while new bluegrass bands come and go, these are classics with staying power. Their songs resonate with many fans and are very catchy. There have been multiple generations of bluegrass bands and multiple subgenres, yet when people think of bluegrass, they think of the best groups of the genre.
This list includes both classic and modern / contemporary bluegrass musicians and bands, as well as the names of the places where each got its start. That said, it's up to you to determine what are the best bluegrass bands. If you notice that a band is missing from this list feel free to add them. This list answers the questions "who are the best bluegrass bands of all time?" and "who is the greatest bluegrass musician ever?" If you know enough about the genre, please vote based on the quality of the band's music instead of just voting for the most popular bluegrass bands that you might've heard of.