Adding vocal harmony to a Tears for Fears song

One possible approach to it, anyway

My theory students are going to be writing vocal harmonies for one of their assignments. To give them guidance, I will be talking through one possible approach to adding harmonies to "Shout" by Tears for Fears. Here's the original song:

Here's the acapella.

I'm not arguing that this song needs harmony vocals; it's just a good teaching example because it doesn't have any. Also, the melody and chords are pretty simple without being boring.

There are endless possibilities for harmonizing a vocal. I approached "Shout" using a reliable formula: one harmony part a third above the melody, and another a fourth below the melody. You can see and hear the result in this score video. I explain what's going on below.