BartK o confuse matters more 😉 the words tonic, dominant, and subdominant are used in two different senses
I read the whole thing but am quoting the first line for brevity.
I once worked with a description of an internship of a dental assistant student in Europe. The very first thing she had to learn was the names of all the tools, and where they were placed on the tray. Later she could prepare different trays for the dentist, and hand him the tools he asked for, and going on to more complex tasks. This made me think of theory, and just knowing what things are called where they are.
At this point, Sophia, you are just learning some names and where those things are, so that if someone refers to it, you can find the thing. The link I gave, the gentleman referred to the "mediant". It's actually the first time I've heard anyone refer to it, but I knew what he meant because I had once learned what you're learning. I haven't found that one particularly useful tbh.
The thing about music is that it's not a static thing that came into existence one day and has stayed that way ever since. People have been tweaking, inventing, reinventing, discovering. They find things that sound good and use those patterns: then the theoreticians come along and set those patterns into stone creating rules; then creative musicians come along breaking those rules, and the original musicians say "Well no, I never meant this to be a rule." And we get to swim in this creative brouhaha.
There are patterns; they do exist; they do help us orient and find our way. There are also many angles to a same thing.
Sophia Up to now, I found chords a mystery. I mean, of course I understand the concept... but I didn't understand how it applies to classical music as well. Just now my book explained the Alberti bass and suddenly it makes sense that the C-G-E-G sequence is the "tonic chord" (If that is the correct expression). Then B-G-F-G is the dominant septime. Something I heard a LOT throughout my life, but never understood
Those who learned these things early on may be dismissive of them, but those of us who just wended our way through nameless, unidentified" "sensed and felt" things, probably don't realize the freedom and clarity this gives. I can identify with this.