Girolamo Frescobaldi - Cento partite sopra Passacagli

This is one of the most remarkable pieces of instrumental music written in the 17th century, an early example of the keyboard passacaglia which would be taken up and modified to have less fantastic variety by the Couperins and J.S. Bach and others who came after. The interspersing of long and fantastic variations that clearly follow the passacaglia form with, first what is recogizable as a courante (corrente) and then with contrasting cicconas and sections in contrasting tonality is pretty remarkable and presents a performer with all kinds of interpretive problems of how fast to play the contrasting sections.  I wonder if it is a written out attempt at reproducing the original passacaglia which was improvised by a musician - probably a guitar player - on the streets.   Needless to say, the performances of it available on Youtube are hardly uniform in how they approach these.  I'll give you two.

Yoanne Moulin, virginal

Harpsichord player is unidentified.

There are other performances at Youtube.

The score can be found beginning on page 77 here.