baryton
noun
bar·y·ton
ˈber-ə-ˌtän,
ˈba-rə-
plural barytons
1
: a stringed instrument of the 17th and 18th centuries similar to the bass viol with a fretted fingerboard, six or seven bowed strings, and numerous sympathetic strings behind them
He also had to provide music of all kinds for the establishment, and composed … a hundred and seventy-five works featuring the baryton, the Prince's favored instrument.
Andrew Porter, New Yorker, 22 Apr. 1991
Andrew Porter, New Yorker, 22 Apr. 19912
usually Baryton [borrowed from German] : an organ reed stop of 8- or 16-foot pitch
barytonist noun
ˈber-ə-ˌtä-nist
ˈba-rə-
plural barytonists
Even in today's "authentic instrument" climate you don't exactly run across barytonists every day. Barrymore Laurence Scherer, Wall Street Journal, 26 Aug. 1997
Barrymore Laurence Scherer, Wall Street Journal, 26 Aug. 1997 
Word History
Etymology
borrowed from French & German; French baryton, borrowed from German, literally, "baritone" (in various senses), borrowed from Italian baritono
First Known Use
1878, in the meaning defined at sense 1