Signs that stand for notes
Every ornament is a macro
Ornament signs are not mysterious — they are abbreviations for written-out notes, the way a contraction stands for a phrase. Pick a sign and watch it decompile: the symbol on the left, the literal notes it stands for on the timeline, played in sync. Same base note (C) every time; the only neighbours involved are D above and B below.
What to notice
They are all neighbours. Every ornament here is built from C and the notes one step either side. The differences are purely rhythmic: how fast, how many, and whether the decoration lands before the beat or steals time from it.
The grace-note pair. The acciaccatura (slashed) is crushed in as fast as possible; the appoggiatura (unslashed) leans, taking half the main note’s time. Same two pitches — opposite characters.