We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
"Modulation is the essential part of the art. Without it there is little music, for a piece derives its true beauty not from the large number of fixed modes which it embraces but rather from the subtle fabric of its modulation."
Charles-Henri Blainville (1767)
If a reader has a more comprehensible explanation than Wikipedia has, let me know.
Instead of an explanation, let the ear hear: Lucy in the Sky with Diamonds by the Beatles, which includes three different keys in the first minute: A, Bb, G.
Music may or may not have modulation. Most popular songs just use chord changes in a single key. But music doesn't even require chord changes. Sometimes the words do all the work, sometimes the rhythm. Listen to Harry Nilsson's catchy Coconut. It's just one chord, C7.
I'm no expert on Music, I like what I like and don't care for the rest. I like a lot of classical music but not all of it. I grew up during the Beatles era and don't care for a lot of what they produced including Lucy in the sky. Don't get it, doesn't work for me. Hey Jude is another one that puzzles me, like were they high on drugs? Lousy music, stupid lyrics. But what do I know.
Yellow Sub too!
"Modulation" just means a change of key. A "key" is the starting and ending ("tonic") note of a musical scale. So if you change the key, what used to be the tonic note now has a different role to play. It basically give a different perspective on the musical landscape, and can be used to create many different emotional effects. Modulation can often sound surprising, especially if you are listening carefully, or create a sense of tension or release. The fact that most popular music rarely contains any but a few routine or predictable modulations, or none at all, is part of the reason for its typical lack of depth and subtlety. Note, all this applies chiefly to "Western" so-called "tonal" music, not Asian or modern "atonal" music. You don't have to be a musician to hear the difference there!
You can learn to play intruments w practice, you can't learn voice, u either got it, or u don't, it's a gift from God. My favorites are Maria Callas, Hank Williams,David Bowie, Patsy Cline, etc. I'm sure u can come w ur favorites also