Bluegrass question: Describe what the difference

is between 1st, 2nd, and 3rd generation bluegrass? I want to be able to spot the differences in the music. I love this type of music it comes from the heart and soul. I listen to 80% of this type. I believe its 3rd generation that I listen to alot. Is their anyone out there that shares my same listening tastes?
Yeah there's a few here (maybe more). Just guessing about your question, but here goes: 1st generation could be Bill Monroe (who invented the term), Earl Scruggs, Vassar Clements, Stanley Bros., etc. 2nd generation would be Ricky Skaggs, Mark O'Conner, Emmy Lou Harris, New Grass Revival, David Grisman, etc. Not sure about 3rd; maybe Patty Loveless?
Nickel Creek would definitely be third generation. How about Allison Kraus?
I also love bluegrass and country (Americana) music. I am surprised at how many audiophiles don't care for this music as it is some of the best "sounding" available.
I've played Bluegrass in bands for 35 years and here is the breakdown : 1st generation is the original 8 "Name " bands--- Bill Monroe, Flatt and Scruggs,Stanley Bros., Jimmy Martin,Jim & Jesse,Country Gentlemen,Reno & Smiley and the Osborne Bros. More tomorrow(gen. 2) John
Though these terms are new to me I'll throw in my 2 cents as to where the lines would be drawn.

I'd agree with the others about 1st generation being the originators Bill Monroe, Flatt and Scruggs, etc. These guys kicked up the old-timey sound to have a very strong drive and beat in much the way rock and roll sprung from blues.

The 2nd generation would be the bands that expanded the music to include more complex or folky songs with more chords and harmonies and such. This would include the Country Gentleman, Kentucky Colonels, Seldom Scene, the New South.

3rd generation would be the bands that added longer jams and more complex rhythms to the sound. This includes New Grass Revival, David Grisman Quintet, and the more recent Jamgrass bands like String Cheese Incident and Leftover Salmon.
Gentle people, just get in you cars and your jets and head to Nashville to hear the difference. Take you all over to the Stagecoach Inn on Sunday nights, and not only will you hear the difference, you will see the difference. Old timers usually sit out front and play, Newgrass boys and girls take up the rooms in the back. The only thing is, I do believe that the likes of Earl Scruggs, Dave Grissman, Randy Scruggs, John Hartford(RIP) would take some, though not much, offense at the pidgeon holing going on here. If anyone in bluegrass is "generationless" it is Earl Scruggs. Pop in the Earl Scruggs and Friends CD and I think you will hear that. And where Nickel Creek is 3rd generation(at least) of Bluegrass, their style is probably more traditional than that of Bella Fleck or Mark O'Connor lets say. I think maybe determining what is NewGrass, BlueJAZZ, and traditional might be a better way to slice it up. Either way or anyway, some of the finest musicians in the world, and its great they are finally getting some of the credit and money they deserve.
Read this months Stereophile-'Building a library'.