The implementation of the Helmholtz notation is pt. erroneous. Helmholtz notation does not prefix commas with octaves lower than the great octave (contra octave, subcontra octave, etc). The commas are suffixed, though the note name is still uppercase.
// Expected to throw:
teoria.note(',C') === teoria.note('C1');
// Actual result
true
The implementation of the Helmholtz notation is pt. erroneous. Helmholtz notation does not prefix commas with octaves lower than the great octave (contra octave, subcontra octave, etc). The commas are suffixed, though the note name is still uppercase.