Facsimile of Sanz' table of Abecedario chord names. http://purl.pt/17285/4/m-871-p_PDF/m-871-p_PDF_24-C-R0150/m-871-p_0000_capa-capa_t24-C-R0150.pdf |
Well, this promises to be my most arcane and rarely viewed post.
In the 17th century, guitar chords were indicated by an apparently arbitrary letter, in the system called abecedario (in Spain) or alfatabeto (in Italy). It bears no relationship to the chord names that we use nowadays. Gaspar Sanz was one of the composers who adopted this system.
Out of curiosity I made a concordance DOWNLOADABLE HERE for converting abecedario chords to ukulele chords. There might be someone out there in the æther who finds it useful.
NB On 7 Feb 2018 I uploaded a revised version, so if you have the old one, please delete it.
By the way, the little runic marks along the lowerlines of the Demostraçion in the facsimile refer to direction of strum (rasgueado): the tick under the line means start at the bottom of the chord and strum UP, whilst the upper tick means strum DOWN.
Happy strumming!