Tommy Ramone, one of the founders of The Ramones is doing bluegrass now under the name Uncle Monk.
He's the guy with the mandolin and the old-hippy thing going on.
This is what their site says about the duo:
Uncle Monk’s music is rooted in old-time and bluegrass influences. To this mix they have added unique musical textures to create a sound with a new sensibility. “We are working with what feels natural to us.” says Ramone. “We are making use of string-band instrumentation along with alternative rock flavorings. We use mandolins and other stringed instruments to add texture and dimension to the overall sound. We have been drawn towards the classic simplicity of string band music, but at the same time we are deeply involved with the aesthetics of alternative music, and we do our best to use our musical influences to create an original style. There is a similarity between punk & old time music, both are home brewed as opposed to schooled, both have earthy energy, and there is a certain cool in old time music that is found in the best alternative acts.”
You can hear this stuff at: