A modern Mexican vihuela has five strings, and the modern vihuela tuning is A-D-G-B-E, with the A, D, and G strings tuned an octave above the guitar. The historical Spanish vihuela, which was popular in the 15th century, had either five or six strings, tuned G-C-F-A-D-G or C-F-B♭-D-G-C.