Composers down through the ages have latched onto each other's melodies, and turned them into whole new compositions. In Beethoven's day, variations on a popular tune -- especially one from a favorite opera or oratorio -- sold well to the burgeoning home music-making market.
The Diabelli Variations began with a solicitation from publisher Anton Diabelli, who was trying to raise money for families of men killed in the Napoleonic Wars. Diabelli sent a waltz he'd written to dozens of composers, asking each of them to write a variation for a set to be published and sold for the cause. At first, Beethoven wasn't thrilled by the idea, but he did contribute a variation to Diabelli's collection. Eventually, Beethoven sat down and wrote 33 variations on Diabelli's simple waltz; the Diabelli Variations are now considered one of his piano masterpieces.
1. 33 variations on a waltz by Diabelli in C major (Diabelli Variations)
2. 12 Variations for cello and piano in G major on Handel's "See, the Conqu'ring Hero comes" (from Judas Maccabeus)
3. 7 Variations for cello & piano in E-flat major on Mozart's "Bei Männern" (from The Magic Flute)
4. 7 Variations for piano on "God Save the King"
5. 5 Variations for piano on "Rule Britannia"
Bonus more obscure set of variations:
Variations for two oboes and English horn on "Là ci darem la mano" from Mozart's opera Don Giovanni
Bonus set of variations on Beethoven's own great theme:
15 Variations and a Fugue in E-flat major on an Original Theme ("Eroica Variations")
Below: Alfred Brendel plays the Seven Variations on "God Save the King"