AS I live in Nashville, have done some work in the Country industry, and know some of the players here, I can give some insight to bass in Country Music these days.
Nashville was particularly driven to new instruments by JD at Corner Music, certainly the 'Pro Shop' here in town. JD at one time has stocked exotic basses by virtually every maker at one time or another. In the 80s and early 90s, it was not uncommon to walk into a room full of Pedullas, the old Tobias', Spectors, etc. More recently, following the overall swing to bolt-neck guitars, you see Custom Shop Fenders, MusicMans, Laklands, etc. And corresponding style amps: SWR, Eden, Euphonic, GenzBenz, Aguilar. This drove a certain amount of change.
Also, with so many players working for 'name' acts, there's always been lots of 'endorsement hogs'. Carvin made big inroads this way. Lakland as well. To his credit, Sterling Ball requires the whole band use his axes, or no one player gets a deal. And he polices this very closely, which believe me, is uncommon. I've seen friends of mine in different ads for different instruments in the same issue of various guitar mags over the years.
Nashville is also home to Gibson, Guild's custom shop, Summer NAMM. There's a lot here in terms of the business/manufacturing side. Yamaha's Artist Relations are based here.
There's a huge range of players, from Victor Wooten to Dave Pomeroy all the way down to hillbilly upright beaters. The recording scene in master sessions is driven by guys like Glen Worff and Michael Rhodes. David Hungate lives here. These guys have cartage bring over trunks of basses to the big sessions, from DanElectros and funky old EB-Os, to current axes. The quality of the big studios is excellent, including Glen Meadows' MasterFonics, as good as anything in NY or LA.
Believe me, when you can go to the Grand Ole Opry on the weekend and see plenty five- and six-string basses onstage, this is a more sophisticated market than people imagine who aren't familiar with us.