**III - A practice of analysis in the tonal harmonic discourse from Bach to Wagner**

TWO CATEGORIES OF CONSTANTS

Drawing on experience "in the field" with this outline for harmonic
analysis and having examined, here and there, the corpus of works from
the repertoire Bach-Wagner, I was lead to identify two broad categories
of constants: on one hand, **formulas**, on the other, **sequences**.

**A) Formulas**:

1. DEFINITION OF A FORMULA

Let us recall that the harmonic formula corresponds to a fragment of
the discourse with a high rate of recurrence in the tonal repertoire, a
fragment consisting of at least three functions (explicit or implicit
in the case of a final unresolved dominant) which result
in the unequivocal designation of a principal or secondary tonic.