The Ruggiero, or bass of Ruggiero, is a melodic-harmonic scheme on an ostinato bass very popular in Europe between the second half of the sixteenth and the first half of the eighteenth century, used in numerous compositions both vocal and instrumental.
Cadenzas from the figured bass period: extensions of the Cadenza lunga and doppia (Ruggiero)
At the beginning of the 16th century, the Italian poet Ludovico Ariosto wrote the verse poem Orlando furioso (The Raging Roland), which was soon widespread, especially in Romanesque countries. In Italy there were many sections of this epic have been shown to be sung soon (and thus represent an early one stage of development of the later emerging opera).
Above all, the line "Ruggier', qual semper fui, tal' esser voglio" became a kind of hit. Ruggiero is a hero of this epic (in English "Roger").
The 8-bar Bass of this aria was used as an basis for many other vocal and instrumental pieces (including at Diego Ortiz, Sigismondo d’India and Girolamo Frescobaldi.)
In detail, this bass exists in different versions, all have in common that they are pretty
frequently cadence to degree I (three times in 8 bars). An early form of the final turn in the 7th / 8th Clock looks like this (e.g. belongs to Benedetto Ferrari).
Mostly, however, the movement of the bass is made more fluid (the upper part can do so
assume different courses, here two variants):
The French Wiki says: The bass is generally in G and 8 short phrases.
Goldberg Varitations J.S. Bach