Around the turn of the century (I mean late 19th.
to early 20th., not now), great effort was made to devise every
kind of banjo to replace other string instrument. There were
guitar-banjos, mandolin-banjos, ukulele-banjos and some more.
Banjos were made in every size, piccolo, ladies, banjaurine,
giraffe(regulqr neck on piccolo pot) etc. and even the bass-banjo
were made. A regular banjo has 5 strngs, but 7, 9, or even 13
string banjos were made(these were mostly made in the UK.)
I'm not colleting or playing all of them, but here are some.