Lots of fodder for discussion here. I'll stick my neck out and say that the poster who called the "commercial" background "too restrictive" is not quite accurate. Basically, bluegrass started life as a commercial "sound," sought for the purpose of claiming a niche in professional music. Monroe was looking for a distinctive and easily-recognized sound for his various bands, and finally hit "it" when he put together the '45-46 band with Flatt and Scruggs and Wise. When other bands, such as the Stanley Brothers, started to copy his sound, he was not pleased, and he was less pleased when Scruggs and Flatt left the band and subsequently formed their own. It was years before he became comfortable with the moniker "father of bluegrass." It was always a commercial music.

However, once it hit the airwaves, through radio and records, its infuence was felt even among down-home (non-commercial) musicians. Archival recordings of banjo players who never had any commercial asperations show the influence of Scruggs in particular, and bluegrass in general. So, yes, there are non-commercial musicians who play bluegrass for their own enjoyment, but without the commercial performance nature of the style, it would have been at most a regional style, and possibly not even collected by folklorists.

But country music as a whole has always been beholden to the record and radio media, from those early days of Fiddling John and the Carter Family and Ralph Peer, whose idea it was to make forays into the south to record the indigenous music and sell the recordings back to those same people (sort of a living example of a consultant -- one who asks you for a number and then sells it back to you). Peer, in fact, was responsible for changing the sound of the actual music, because his concept of a string band didn't include the piano, so those bands who used them (such as Charlie Poole's band) did NOT do so on the records they made, leading to the idea that the classic old-time band included fiddle and banjo, plus guitar and sometimes other instruments, but not piano.

Anyway, like I said, there's lots of fodder to chew on in this topic and its related ones (commercial influence on styles, the position of the musician in rural communities, urban vs. rural stereotypes, etc.).

Bob Clayton