This John Campbell single Bb horn, now owned by Jesse Boyd, includes a muting valve and F extension. Campbell spent summers at George McCracken’s shop in the mid-1980s, apprenticing and learning the craft firsthand.
Jonathan Parrish shared the following recollection:
John and I built our Bb horns side by side. I think it was the summer of 1985 because I finished mine in time to play it as my main horn for the first year of grad school at Peabody. I’m not sure my teacher was thrilled about the switch because I got assigned a lot of low parts in orchestra - 2nd horn Ravel Left Hand and Mahler 1 - and he had me learn Strauss 2 on it. I went back to my Mc8D for year 2 and used the Bb for classical and baroque rep. It’s a great horn for Brandenburg or a Mozart concerto.