There are three main styles of mandolins commonly found here in
the United States today. Of the three the Neapolitan, sometimes
called the bowl-backed mandolin is the closest to the original
historical instrument. As the mandolin evolved into the instrument
we have today it became thinner, and the top changed its profile a
couple times. So today we have the Neapolitan the flat top and the
carved top or arched back mandolins. Here in the United States we
see the carved top mandolin more times than not. It is used
extensively in
bluegrass and country music. The difference between the flat top
and carved top is exactly what it sounds like. Building the flat top is
very close to guitar as far as techniques of constructing the top. It
starts with a flat thin piece of wood. The carved top starts with a
somewhat thicker piece of wood about an inch or so thick. The
excess is actually carved off thinner on the edges and thicker in the
center. The standard mandolin has 4 courses of strings with two
strings in each course tuned in unison, for a total of 8 strings.
Although the number of strings on a mandolin may be anywhere
between 4 and 16.
There are more types of banjo than you might think and for the
most part which one you choose depends on what flavor of music
you prefer. The standard 5 string banjo neck is 26 and ΒΌ inches
long with 22 frets and 5 strings. You have other neck length
choices though when selecting a banjo ranging from 32 and 7/64th
inches with 25 frets to 22 inches and 17 frets. There are tenor
banjos with 21 inch necks with 17 and 19 frets. There are also 4
string plectrum banjos and shorter 4 string versions known as
Banjo Ukes with 16 frets. These are all tuned differently and some
have resonators and some are open backed. Then come the 6 string
and believe it or not the 12 string banjos and don't forget the bass
banjo. As if that isn't enough there are a multitude of different
woods and materials used during construction to create different
tones.