Wikipedia
A guitalin is a Northern American folk instrument that is a part of the lute family, having four courses of strings. Its fourth course is tuned to an octave while the remaining courses are tuned in unisons. The instrument can be either finger picked or plucked with a plectrum. It was invented in October 1962 by Lyle Mayfield of Greenville, Illinois. The guitalin is a non-traditional, hybrid folk instrument, as it incorporates features of multiple traditional folk instruments into one. While the original tuning consisted of a G chord in root position, the standard tuning of the guitalin which was adopted is a C chord in second inversion. Another common tuning is a second inversion G chord.
The timbre or tone quality of the guitalin can be described as a combination between a banjo and a mandolin, while the name of the instrument is derived from the combination of the names of the guitar and mandolin. The shape of the body of the instrument is an elongated trapezoid about the length of a standard guitar body.
From the time it was invented until Lyle's death in 2012, there was much experimentation with several configurations of instruments based on the guitalin and guinjo (another of Lyle's inventions). Among these experiments were the fretted fiddle or "friddle" or "guiddle", an 8-string fiddle, the dobrolin, the triplin (an instrument Lyle disliked, recorded once, then scrapped), an electric ( solid body) guitalin, and even a full-sized, upright guitalin bass. Other notable Mayfield instruments include the guinjo (1974), a bass mandolin (1974), the Coffee Can Lid Banjo (1974), a Commodophone (a spoof instrument using a toilet seat for a top), the Echo Guitar (1992), the Mayfield Guitar (1998), the Mariachi bass (1998), a variation on the hard-top banjo (2006), the Mayfield Pear Guitars (2005), a variation on the Manjo (2006), the Round Cornered Guitalin (Martin Smith, 2006), the Round Head Guitars (Martin Smith, 2007), and variations on the Mandola (2008) and the Dreadnought Guitar (2008).