The banjo rose to prominence in the antebellum south, and as a result, it never made it on the radar of most "classical" composers. We could argue about the validity of the term "classical" music, since historians have picked a seemingly arbitrary date range of 1700 - 1950. The genre also includes any music that is patterned after that era of classical music.
But that said, contemporary American composers have started to take the instrument seriously. This is an interesting development. It comes at a time when composers like John Mackey and John Carigliano are including all kinds of bizarre instrumentation in their band and orchestra music (ex. dragging a bouncy ball across a timpani), so perhaps we shouldn't be surprised.
The banjo's primary use as a rhythm instrument somewhat disqualifies it from the more lyric demands of modern orchestral or chamber music though. That's why I was so surprised when I came across “Flatiron," by the modern composer Marc Mellits.
Here's a link: https://www.youtube.com/watch?v=dVwNV-5LbNk
I was especially intrigued to come across this, as John Bullard, the banjo player and driving force behind the banjo's emergence on the classical scene, is on faculty at Cairn University in Philadelphia. I'm a guitar student at the Philadelphia Piano Institute, of all things, so I'm hoping we'll get a local performance some day.
In summary, check out the work of Marc Mellits. These contemporary "classical" pieces for banjo will never replace its sacred place in folk, rock, and other genres, but I am fascinated to see where composers decide to take the banjo next. It's a fine instrument, and brings plenty of joy to guitar students, hobbyists, and casual listeners alike.
'Polka on a Banjo' 9 hrs
'Cellphone Gurus...' 10 hrs