Around the turn of the last century, mandolin orchestras were popular, incorporating the mandolin family of instruments (mandolins, mandolas, mandocellos, and mandobasses) as well as guitars.
Gibson, and other companies, produced mandocellos in the early 1900s. Mandocello was THE baritone stringed instrument of that period, long before the baritone guitar was created. When mandolin orchestras declined in popularity, so too did the popularity of the mandocello (as well as the mandola). However, the mandolin continued to be an instrument of choice for several genres of music.
Mandocellos became obscure and nearly forgotten as the guitar became the dominant instrument in popular music. Through the years, however, some modern musicians have added mandocello to their music. Composer Geoff Goodman features both guitar and mandocello in his compositions. Patterson Hood, of Drive-By Truckers, plays a mandocello conversion made by Scott Baxendale. Mike Marshall played a mandocello on his collaboration album "Uncommon Ritual" with Edgar Meyer and Béla Fleck. Rick Nielsen of Cheap Trick plays electric mandocellos custom made by Hamer Guitars. Their song "Mandocello" used a standard acoustic mandocello. This song was later covered by Concrete Blonde and released on their album "Still in Hollywood." Jaco Pastorius, bassist for Weather Report, overdubbed a mandocello on their hit "Birdland." Richie Sambora, guitarist for Bon Jovi, used a mandocello on the song "Lay Your Hands on Me" from their acoustic album "This Left Feels Right."
The mandolin family of Instruments, as well as bouzoukis and twelve string guitars, use paired strings (or courses) to provide a more full and continuous sound than a single string would. Paired strings also facilitate tremolo picking, which adds nuance and sustain to the notes and chords.