Barbara's multi-talented musical daughter, Laurie Lewis, celebrated the centennial of the birth of Bill Monroe, the inventor of Bluegrass music, by organizing two successive nights of his music, either written by him or notable for his performance of it. This was at the beautiful newish venue of the Freight and Salvage Coffeehouse, in downtown Berkeley. What was described as the "core band" (Laurie, Tom Rozum, Chad Manning, Patrick Sauber, and a bass-player, filling in for the recently-departed Andrew Conklin) was supplemented by such old friends as Kathy Kallick and Keith Little. We attended both nights.
By now, I am accustomed to the practice of applauding "breaks"--brief solos on a single instrument. When I first began listening to jazz, from about 1940, it was the recorded music of such greats as Muggsy Spanier, Bix Beiderbecke, and Louis Armstrong, and any such breaks in a studio performance were free of audience appreciation. Only when I listened to live music did I hear folk clapping after an inspired impromptu break.
The practice of applauding breaks has certainly spread to Bluegrass. It's commonplace for each solo instrumentalist to take a short break in almost every number. There's a scatter of applause every time--too frequently, in my personal opinion. It has become a routine, and I can't see any change happening in my lifetime. It would take a major change to limit the applause to imaginative improvisation, where the applause really belongs.