Pop Music Through the Ages with someone who knows little about either pop music or the ages

I've been toying with the idea that the pop music from different decades is characterized by its influences or flavors. I can't really examine this with pop music from before I was born since I'm not familiar with it, but I think this theory sort of holds up:
The 1990s: R&B-flavored pop (lots of vocal trills, ballads, etc.)
The 2000s: rock-flavored pop (idk, like Avril Lavigne and Kelly Clarkson or whatever)
The 2010s: electronic music (the stuff they play in clubs, like house or dubstep or whatever. I don't know music terms)-flavored pop. Perhaps as a reaction, folk-flavored alternative music seems to be growing in popularity as well (Mumford & Sons). I am not doing a list like this for alternative music because I know even less about that than I do about pop music.
Also, retro-flavored pop (stuff that sounds like Motown or other music from the 1960s, e.g. Amy Winehouse and Adele) became A Thing in the mid-2000s to the present, as well.

I don't know music well enough to be as certain about pop music earlier than that (as if I'm even sure about the pop music in my own lifetime), but I think it's tentatively like this:
1980s: electronic-flavored pop (Madonna, Michael Jackson, Prince. This kind of electronic means synthesizers [?] rather than the clubbing/remix-music sound popular today)
1970s: folk (Peter, Paul and Mary; Bread, etc.) and rock (The Beatles, The Rolling Stones, etc.)
1960s: rock 'n' roll- (Elvis?) and soul/blues-flavored (Motown, Aretha Franklin etc.)
1950s: idk, rock 'n' roll also? Getting over big band (Elvis?)
1940s: big band
1930s: possibly jazz, medium band, folk (I don't know. All my knowledge of '30s music comes from O Brother, Where Art Thou?)
1920s: jazz, stuff that sounds like classical music to us now
1910s and before: Ragtime?, stuff that is classical music now

At some point Mozart was popular music, dude. Sixteen year old girls probably stayed up at night crying over Felix Mendelssohn.

Michelangelo's paintings on the Sistine Chapel ceiling

On this day, November 1, 1512, Pope Julius II unveiled Michelangelo Buonarroti's frescoes on the ceiling of the Sistine Chapel in Rome for the first time. It took Michelangelo four years to paint them, and he hated it. He wrote this poem about it, which I love because it's one long complaint:

To Giovanni da Pistoia
"When the Author Was Painting the Vault of the Sistine Chapel"

I've already grown a goiter from this torture,
hunched up here like a cat in Lombardy
(or anywhere else where the stagnant water's poison).
My stomach's squashed under my chin, my beard's
pointing at heaven, my brain's crushed in a casket,
my breast twists like a harpy's. My brush,
above me all the time, dribbles paint
so my face makes a fine floor for droppings!
My haunches are grinding into my guts,
my poor ass strains to work as a counterweight,
every gesture I make is blind and aimless.
My skin hangs loose below me, my spine's
all knotted from folding over itself.
I'm bent taut as a Syrian bow.
Because I'm stuck like this, my thoughts
are crazy, perfidious tripe:
anyone shoots badly through a crooked blowpipe.
My painting is dead.
Defend it for me, Giovanni, protect my honor.
I am not in the right place—I am not a painter.

Not a painter! I love him. I went to the Sistine Chapel when I was in Italy, and it was glorious. Absolutely gorgeous and breathtaking. I'm sad he was forced to do it and that he suffered, but I think it was worth it because of the beautiful legacy he left to the world. Think of all the people who have been uplifted by its beauty.

You can read all of Michelangelo's poems here
The text of the poem is from this Slate article, which is excellent and you should totally read it
Image source
History info is from The Writer's Almanac's enewsletter for today