Ken Natton said:
Usually, someone who is described as ‘playing by ear’ is someone who cannot read music at all, and would not have the faintest idea what was meant by ‘a chord of C major’ or ‘a chord of A minor’. All they do is work out how to play something that sounds like the piece that they have heard. I have encountered some people who are astonishingly good at it, and for someone who learned more formally, it is always a mystifying ability.
I think that's a bit of a generalization though. I play by ear, but I also know theory. Technically, I can read music, but I can't sight-read (and I haven't practiced sight-reading)
but I went through several periods of musical development
1. very young, piano lessons, hated it (monotonous)
2. high school, guitar, learned a couple chords, then started studying theory and technique on the internet. But mostly, I was always jamming with a friend of mine who got me interested in guitar. We'd just play. I eventually learned that the scale I had diddle in that i liked was called E minor harmonic and learned about triads and arpeggios and the harmonic series. Picked up the violin and the accordion a couple times, but never purchased my own. I love the breathing rhythm of the accordion though. During this phase, I would also fill cups up to different levels and try to get them into an A minor scale. I also remember using a microphone and a wah-wah pedal on my piano. I was very experimental with tonality and timbre at the time.
3. college, started my physics degree with a minor in music (later went from BA to BS in physics and dropped music, but not before getting through a year of theory and ear training; aced the theory, couldn't sing or sight read in the ear training, but never really practiced it and still don't have much interest. I actually think classical musical notation is terribly unintuitive and out of date. I still use tabs.)
4. musical death (physics degree took-over for a couple years)
5. mandolin bluegrass revival + drummer to jam prog rock with. Miss having a rhythm guitarist though.
wouldn't the circle of fifths and the way it all comes together be much more elegant in a mathematical formulation rather than letters with sharps and flats?