I’m not going to pretend that this is a “best of” list for roots music in 2015.  With so many things thrown on my plate this year, I  haven’t had the time to sample as widely as I would like.  (Come to think of it, the last time I felt comfortable enough to publish a “best of list” was 2013!) But I’m very comfortable with a favorites list that just says, “Hey, I like these and I hope you will too.” So with that caveat, let’s see what’s made the cut. The SteelDrivers:  The Muscle Shoals Recordings – I’ve loved this Nashville-based bluegrass band for years, even as they have moved through personnel changes that included their lead singer and main songwriter.  (More on that later.)  The Muscle Shoals Recordings is really the first album where Gary Nichols stepped out on his own as the lead voice for The SteelDrivers – no longer in Chris Stapelton’s shadow. Singer-songwriter Peter Cooper describes it this way: Right there, at two minutes and ten seconds into the first …