Mandolin-banjo John Farris for an instrument with 8 strings. The Farris banjolin was offered in soprano, alto, tenor, and bass models. However, he "converted it to a four-string instrument," maintaining the mandolin and violin scale length and tuning (GDAE). Banjo hybrids normally take their names from the Banjo- prefix, and then the second half of the other instrument's name, such as banjocello, banjo guitar, and banjolele which implies the banjolin is a sort of mandolin/banjo hybrid. In the advertisement, Farris did not mention where the name came from, but did say that it was "fingered like the violin." Banjolins should not
Mandolin suit them to Cai luong opera music. In the mid-1930s, they made concave frets, scooping out extra wood between the frets, making the space between them deep and to allow the musicians to bend the notes, and stringing them with four single strings. Musicians Hai Nén and Hai Nhành were associated with the instruments, possibly being the first to use them. The "sunken-fret mandolin" (mandolin phím lõm) did not meet the musical needs as well as the sunken-fret guitar, because the mandolin's rigidity made it painful to get the same effects from the strings. Also the mandolin's narrow fretboard made