Eleven-string alto guitar

The eleven-string alto guitar (also known as altgitarr, archguitar, or Bolin guitar) is an extended-range classical guitar developed by Swedish luthier Georg Bolin in the 1960s.

11-string alto guitar
Head of 11-string alto guitar

Original Bolin instruments are now rare and valuable.[1] The Bolin alto guitar most often has eleven strings, but Bolin also made a thirteen-string version.

The 11-string alto guitar is a multi-string classical guitar, which generally refers to classical guitars with more than six strings. Classical guitars with extra strings can have from seven to 13 or more strings.[2] However, an 11-string is the most useful for performing lute music, particularly Bach and Weiss. The first six strings are tuned in the same intervals as the normal classic guitar. Therefore, a musician can play with conventional fingering on those strings.

In the United States, luthier Walter Stanul makes performance instruments ranging from 11 to 13-strings called the Archguitar. The design and the body shape of this guitar is similar to the vihuela, and thus it is fundamentally different from the Bolin design.[3]