The circle of fifths can be studied (and often is) with the loci method. Visualising the circle of fifths, with the relative minors, as a real space that can be moved around in is very helpful.
Music theory is full of little mnemonics, and is itself a sort of system of mnemonics:
Instead of an infinite gradation of frequencies, they are reduced to 12 repeating notes within each doubling, so that a 440 Hz vibration is an A, as is a 220 and an 880 Hz vibration.
If instead of doubling a frequency, we add a half to it again for a 2:3 ratio, we get a perfect fifth. By repeating this process (with some fudges) we end up with twelve notes, the circle of fifths, and the vast majority of Western music.
Rather than simplistically giving these 12 notes 12 letters, they get 7, in a clever system that allows for all 24/30 major and minor scales to have one of each letter A to G.
The 7 notes in any particular major or minor scale can be combined with each other to form chords. Major and minor chords each share a root and a fifth; the third is different by a single semitone. The combinations of three notes that sound nice together are thus greatly simplified.
Once the circle of fifths is internalised, all 24 (or 30 - ask Wooten) major and minor chords can be constructed, transposed, and played with.
So, when an experienced musician hears a song they can put all of that background to work. Instead of remembering each indivudal note played, the notes are chunked into chords, hich are chunked into keys and progressions. Once contextualised with similar pieces the memorisation becomes easier and easier. By the time all of that contextual data is assimilated, with music that is _felt_, there isn't much need (I'd imagine) for good musicians to use memory palaces for fingerings or performance details. I'd say a lot of that knowledge is in the hands, the breath, and the whole body.
Music theory is full of little mnemonics, and is itself a sort of system of mnemonics:
Instead of an infinite gradation of frequencies, they are reduced to 12 repeating notes within each doubling, so that a 440 Hz vibration is an A, as is a 220 and an 880 Hz vibration.
If instead of doubling a frequency, we add a half to it again for a 2:3 ratio, we get a perfect fifth. By repeating this process (with some fudges) we end up with twelve notes, the circle of fifths, and the vast majority of Western music.
Rather than simplistically giving these 12 notes 12 letters, they get 7, in a clever system that allows for all 24/30 major and minor scales to have one of each letter A to G.
The 7 notes in any particular major or minor scale can be combined with each other to form chords. Major and minor chords each share a root and a fifth; the third is different by a single semitone. The combinations of three notes that sound nice together are thus greatly simplified.
Once the circle of fifths is internalised, all 24 (or 30 - ask Wooten) major and minor chords can be constructed, transposed, and played with.
So, when an experienced musician hears a song they can put all of that background to work. Instead of remembering each indivudal note played, the notes are chunked into chords, hich are chunked into keys and progressions. Once contextualised with similar pieces the memorisation becomes easier and easier. By the time all of that contextual data is assimilated, with music that is _felt_, there isn't much need (I'd imagine) for good musicians to use memory palaces for fingerings or performance details. I'd say a lot of that knowledge is in the hands, the breath, and the whole body.
Disclaimer: I am not a very good musician (yet).