Rachmaninoff's Corelli Variations

The theme of Corelli variations is familiar melody, and it seems I heard before somewhere. After doing some research on the piece, I remembered that Liszt used the melody in his Rhapsodie Espagnole. The original theme is a set of variations of the European musical theme, ‘La Folia,’ an early Portuguese dance. Several composers used the theme in their music, such as J.S. Bach, Scarlatti, and Liszt.
Rachmaninoff attributed it to Corelli, because of its use in one of his violin sonatas. The Corelli variations Op.42 was composed in 1931. It is a group of 20 variations. The first thirteen variations are all in D minor. They are followed by an Intermezzo that precedes two more variations in D-flat major. These D-flat major variations are the “heart of the work”. The last five variations and coda return to the original key of D minor.
The Corelli variations is as Rachmaninoff's later work, composed in a more emotionally detached style. Rachmaninoff sought a greater sense of compression and motivic development in his works at the expense of melody.