The next video is from Nickel Creek. This band varies in my opinion because the songs don't sound bluegrass or very "country". The instruments are similar with upright bass, acoustic guitar, mandolin, fiddle, but the sound is very modern. One thing they use very well is vocal harmonies which is reminiscent of bluegrass for sure. Check this song called "Speak", one of my personal favorite groups of all time. p.s. -- you may recognize the mandolin player Chris Thile from The Punch Brothers (previously posted video).