Original: Two famous variation sets from the Baroque era, both for harpsichord, are George Frideric Handel's The Harmonious Blacksmith set, and Johann Sebastian Bach's Goldberg Variations, which together with Beethoven's late variations are widely considered to represent the pinnacle of the form.
Simplified: George Frideric Handel wrote a famous set of variations for harpsichord called Harmonious Blacksmith, and Johann Sebastian Bach wrote the Goldberg Variations, which was a set of 30 variations: a very long piece of music.