Quick synthesizer with harmonics

I've been studying synths and recently this guy's tutorial really make things click for me. The way he shows the sound in the frequency spectrum really shows what makes the sound, and explaining harmonics was really interesting.

Tonight I thought I'd give Cursor a chance to create a quick synth from scratch to play with harmonics. I also wanted to visualize the frequencies. Here's the Cursor came up with really quickly while the kids brush their teeth: