Fantasia/fænˈteɪʒə/ Definition 1 of 4Pro Tip 1/3Music Freedom Fantasia in music implies creativity without strict structure. His fantasia on the piano was spontaneous and unpredictable. Pro Tip 2/3Classical Roots Though free-form, a fantasia often references classical melodies. She enjoyed the fantasia that revisited themes from Mozart. Pro Tip 3/3Concert Usage Fantasia is common in formal concerts, not casual music sessions. The orchestra's program includes a fantasia tonight.