Fantasias of yore were free musical compositions which were structured according to the composer's fancy and tended to be wonderful sprawling journeys, less organised than symphonic or concertato forms. Possibly an early version of what much later became known as (whisper it) prog.
My piece below is similarly in the Fantasia (non)-style. Recorded onto a minidisc recorder in my lounge, played spontaneously on a Kemble minx piano in the winter. One of the few other pieces of any note which I often play by heart is Mozart's Fantasia in D minor and my ears can hear places where Queen might have found some inspiration back in the day.