A beautiful example of a Fantasia on a theme by another composer is Vaughan Williams’s Fantasia on a Theme by Thomas Tallis. My composition is a symphonic fantasia on the theme of the Kyrie of the Missa Mi-mi of Johannes Ockeghem. This theme measures 11 bars, has a duration of approx. 40”, and has a beginning motif in the bass voice (EAAE) that is recurring in other parts of the mass. This theme can be heard in full length 3 times in my composition, firstly at 2’40”. All the material I used in my composition is derived from these 11 bars. Ockeghem was one of the most respected composers of the 15th century and one of the pioneers of Western polyphony. He was born in what is now Belgium, but was at that time the Duchy of Burgundy. I discovered his music recently via YouTube and although I am generally not into renaissance music I have become addicted to the religious music of this one composer. I think this is because he composed vertically (he didn’t write out firstly one of the voices like many other composers at that time), but at the same time treated the voices independently, and that all very instinctively without strict rules like the use of imitation. There are no dynamic markings in Ockeghem’s score. At that time the performers knew when to lead and be louder and when not. But the performances of the Kyrie I hear on YouTube are in my opinion rather even (although still beautiful). In my composition I think I managed to emphasize the lines that should be, mostly by doubling the strings by the brass. I scored for triple woodwinds merely to avoid exhaustion during some long tonguing passages. You hear a digital performance using Sibelius 6 and Garritan Personal Ordchestra. A score moving video is on my YouTube channel.