Below is the video from the lesson on May 7, 2020; enjoy! Below the video you will find two versions of the example song Home on the Range, one with the original simple chords and one with secondary dominants. If you have your own favorite melody you would like to try these techniques with, please feel free to do so and share in the comments. I will upload a song for you shortly.

Here is a simple harmonization of Home on the Range using only I-IV-V: https://musescore.com/marcsabatella/home-on-the-range-simple-harmonization

Here is a harmonization using secondary dominants: https://musescore.com/marcsabatella/home-on-the-range-secondary-dominants

Here is a song you can try reharmonizing using secondary dominants: