Why does this tonal scale from 1737 have both F and E♯?

Question

I've recently encountered Jean Féry-Rebel's "Les Élémens". (Check out that wild opening; it's hard to believe it was written in 1737!)

In the fifth measure of the third staff, why does this descending scale include both F and E♯? (Notice that it uses the French violin clef, so the bottom line is G.) It's apparently not a typo; there are more E♯s in the instrument above this one and in the figured bass as well.

In recordings, this E♯ is clearly a half step lower than the preceding pitch, and thus E♮. Is this a byproduct of a particular tuning system? Is it some type of courtesy accidental so the performer doesn't play E♭ (the music did just cadence in B♭)? Or is it something else entirely?

Answer 1

Wow! What you've stumbled upon is not just an impressively early use of a tone-cluster; it's also an impressively late survival of a system of chromatic notation, universal in the Middle Ages and Renaissance, that uses only two accidentals: the flat (written ♭) and the sharp (written ♮, ♯, or various 𝄪-like shapes). The flat is used to denote "low" versions of notes such as E♭, B♭, and F♮, and the sharp is used to denote "high" versions such as E♮, B♮, and F♯. As long as music does not get too chromatically adventurous, these signs are unambiguous. (For instance, Palestrina's output does not use sharps beyond D♯ or flats beyond A♭.)

In the present piece, the use of sharps and flats cannot be globally consistent (for instance, three kinds of D occur), but they are given meaning locally by relation to the main key. They most often represent major and minor intervals above the bass. This usage, in connection with a figured bass, is quite venerable. In fact, the first generation of figured basses, published by early Baroque composers such as Monteverdi, does not have figures at all: only a sharp or flat often placed on the line or space a 3rd above the bass note, directing the keyboardist to play a major or minor triad respectively. (See here.)

Answer 2

Normally there are only 7 lettered notes in a given key. This passage starts with the notes C,Bb,Ab,then G,F,E#,D,C . I do nor know why this pattern was chosen by Féry-Rebel, but this method of notation preserves the 7-letter rule. He does it again in the next passage going upward. This is not apparently a chromatic passage as then the 7-letter rule wouldn't necessarily apply.

Is there an F# in the key signature? Were the passage in the key of G-major or e-minor, it could be a chromatic alteration. It's almost a reversed Phrygian scale on the note. It's also a c-minor scale with the third note as E# rather than as Eb. One more weird possibility is that the E# is really an E-natural with a 3-flat key signature (c-minor or Eb-Major).