The Jarana was originally a native interpretation of the Spanish colonial (i.e. baroque) guitar. I was introduced to the jarana by an "early music" acquaintance; she had a jarana jarocha tercera with a baroque guitar setup, custom built by a Mexican luthier. The main distinction is in the stringing. A normal jarana has eight strings in five courses: g c'c' e'e aa g. The typical baroque guitar has nine strings in five courses: aa d'd gg bb e'. In baroque guise, an extra tuning peg is added to the jarana, usually at the top center of the headstock. I was sufficiently intrigued to try building a jarana myself. Unable to find any plans, I created my own by scaling web photos to a tercera scale length of 580mm.
While the Spanish instrument was built with thin back and bent sides, the jarana neck and body was (and often still is) carved from a single block of wood. Mexican natives would have used whatever wood was locally available, so I did the same. My jarana was carved from a block of Red Alder, from a tree in our yard. The shape was roughed out while the wood was green. After some months of drying, the body and neck were sawed, rasped and sanded to their final shape.
The soundboard was made of 2mm Western Red Cedar, with a rosette of spalted cherry wood in a star pattern. Finding no images of the inside of a jarana soundboard, I guessed on a couple of fan braces for the lower bout. The soundhole braces are attached directly to the body sides.
The fingerboard and bridge were made from a piece of "Tigerwood" from the Rockler Woodworking scrap bin. The tuning pegs were turned from walnut, which was also used for the simple top binding. Like my friend, I decided on baroque guitar tuning, with corresponding light tension strings (ranging from 3 to 4.5 kg). I used D'Addario nylon singles, except for the low D 4th which is a Savarez KF fluorocarbon (to avoid a wound string).
I characterize my jarana as "a very happy instrument". It is bright and jangly, fun to play, and works well in a group of ukuleles!