Harmony + Ping Pong Delay

I created a chord progression based on one that I generated using chordchord.com

The purpose of this exercise was to learn about harmony. I used Tone.js to create a Polysynth and a Part, which is basically a sequence that can be looped over and over again. The composition is very simple but the Ping Pong Delay adds a little charm and complexity to it. I used the collage I created a while back as a cover photo for this to pay homage to the lovely Ping Pong Delay I discovered on the Tone.js site after Max Horwich pointed me in this direction.

Collage by me, chord progression fromhttps://chordchord.com/

Collage by me, chord progression fromhttps://chordchord.com/

Questions for Luisa Pereira in office hours:

  1. I am still struggling with creating visuals that are triggered by Tone.js events. How can I do that? I tried it like this but there was no way to time it so that it only shows up while the chord it playing. I think iā€™m heading in the right direction but not sure what the solution is here.

    if (chord = Eb_chord){
      //   ellipse(12,12,12,12);
      // }

  2. Why does the ping pong ellipse i am drawing behave differently when i remove the photo from the sketch? https://editor.p5js.org/katya/sketches/HyXIzjGn7

  3. in the image below what does iv, iii, etc mean?

Screen Shot 2018-10-27 at 8.24.19 PM.png