I once was asked whether improvisation over a fixed harmonic scheme — like the 12-bar blues — was a new invention of the 20th century.
I started explaining about the passacaglia and the chaconne in Baroque classical music, or the even earlier “ground” in Renaissance England — but these are primarily centered on the bass line and do allow reharmonization (or minor-major interchange, as in the middle section of Bach’s immortal Chaconne in D minor for solo violin).
A more direct equivalent is “La Folia” (literally “the madness”). Below the bass line is given in G minor, and the harmonic scheme spelled out in Roman numeral notation. (CC:BY 3.0 “Hyacinth” from Mediawiki.)
In modern jazz/rock notation — which is absolute rather than relative — this would translate to (in G minor):
Gm | D | Gm | F7 | Bb | F7 | Gm | D | Gm | D | Gm | F7 | Bb | F7 | Gm – D | Gm||
This scheme supposedly originates in a tune called “Les folies d’Espagne” or “La Folia d’España” from the 16th century. For our purposes, the essential thing is that multiple composers from the Baroque era (and later) wrote series of variations over it, which they simply called “la Folia” the way we’d speak of “the 12-bar blues” today. And indeed, group improvisation over the Folia framework appears to have been a thing then, presumably then as now ranging from the sublime to the utterly banal, depending on the musical skill and inspiration level of the performer.
Here is a lecture, with musical examples, about La Folia at Tel-Aviv University, given during the pandemic via Zoom.
Here is Vivaldi’s version (in Baroque chamber tuning, i.e., a half-step down from modern concert pitch):
This is Itzhak Perlman playing Kreisler’s solo violin arrangement of Corelli’s version
One “La Folia” version that movie buffs know as “the Barry Lyndon theme” is of course Händel’s sarabande from keyboard sonata in D minor HWV 437, embedded below in the orchestral arrangement used for the movie:
For a more modern tribute to La Folia, see the closing section of “Force Majeure” by German electronic music pioneers Tangerine Dream, which starts at 15:51 into the movie. (I hope the embed preserves the timestamp, otherwise click here).
Have a nice weekend, shabbat shalom, and enjoy!
UPDATE: J. S. Bach’s quasi-Folia: the aria “unser trefflicher, lieber Kammerherr” (in B minor) from the Peasants Cantata BWV 212: