True. I wouldn't have known I don't have the competency to sight-sing if I didn't try it first. That said, doing the "real thing" is out of my reach until I level up in other areas.
I’m curious if you have heard about Gnu Solfege. I just read about it here recently via the recent “Ask HN: I'd like to learn vocals, any suggestion on how I can do this?”
https://www.gnu.org/software/solfege/
https://news.ycombinator.com/item?id=23359096