Clef and transposition

Introduction

Human voice full range would require an eleven lines staff to be represented

A readable survival of this fictitious staff lies in the grand staff

It clearly appears that the fictitious staff had to be reduced to a five lines staff to become readable.
Actually three staves were extracted from this imaginary eleven lines staff with an assigned letter,namely FCG, called « clef » to keep them distinct

    • The five bottom lines gave birth to the staff labelled F, the clef beeing placed on the fourth line from the bottom
    • The middle (sixth)line along with two lines on each side resulted in the C staff with the clef resting on the middle line (the sixth line)
    • The five top lines yield the staff labelled G with the clef on the second line from the bottom

  • The C staff is the medium register enclosed by the F and G clef
  • F staff is the low register
  • G staff is the high register

Clefs are always placed on a line and give their name to the note F,C or G

There are Seven clefs in usage (like the number of scale notes)

  • One G key
  • Four C keys
  • Two F keys

so a given note may received seven name

Clefs aim to limit to two ledger lines above staff so all clefs but treble key have the same range

Clefs are always placed on a line and give their name to the note F,C or G

Succession of clefs rely on the alignment of the reference pitch A which is or would be in a space

Summary: Clefs have Three functions

  • Name a sound
  • Give the pitch compared to the reference
  • limit the ledger lines above the staff and therefore enhance legibility

Clefs in transposition

Use of clef is especially valuable in transposition
For example: Play a violin /oboe /flute melody with a clarinet Bb .

Clarinet Bbmeans that C play with a clarinet sounds Bb (a tone lower) than violin or oboe C

therefore clarinetist Bb must play a tone higher than written
using the alto clef


Conversely if the oboeist wants to play the clarinet part ,he must play a tone lower using the tenor clefFrom the two preceding examples we notice agreement between clefs<

A complication may occur when transposing from bass clef .The reasoning is the same but the clefs are different

  • Reasoning with treble clefClarinet Bb : I say Bb=C and I write the Bb with treble clef and search the fitting  clef (remember clefs are always on one of the first four lines from the bottom)
  • Reasoning with bass clef
    Clarinet Bb : I say Bb=C and I write the Bb with bass clef and search the fitting clef

Transposition with two different transposing instruments

For example Playing the Clarinet in A part with a clarinet in Bb

The reasoning is the same provide the part to transpose is taken into account.
Clarinet Bb : I say Bb=A   I write the Bb with treble clef and search the fitting clef


Conversely ,Playing Clarinet in Bb part with a clarinet in A

Clarinet A : I say A=B  I write the A with treble clef and search the fitting clef

Important remark Neither accidentals nor register is taken into account by Clef transposition
so B is the same as Bb and E4 is similar to E2

Clef transposition in counterpoint

1°) Voce piena

Clefs in transposition was a common usage in old time.

In renaissance music a common texture named Voce piena was used . It consists of two groups made of two voices an octave apart (ST and AB)
The 2 groups form either a fourth or a fifth

Thank to clefs each voice had the same range notation

Two sets of clefs were used :


    • The Chiavi Naturali set
      that use the Soprano,alto,baritone and bass clefs

    • Tthe Chiavettes set that consists of treble,mezzo soprano,alto and baritone ot tenor clefs

Clef transposition in counterpoint:(cont..)

1°)Voce piena (cont..)

Switching from

    • naturali to chiavette causes a higher third transposition of plagal mode
    • chiavette to naturali yields a lower third transposition of Authente mode

  • other inversions are not valid

2°)Fugue

Subject and answer are similar in notation but the assigned proper clef makes answer  sounds a fifth higher or a fourth lower

Clef transposition in counterpoint:(cont..)

2°)Fugue

The reasononing is always the same
1°) Write a sound in given clef
2°)assigned the name of the desired transposed sound
3°) search the fitting clef

3°) Correspondance of clefs

Stage 1:Assign a name to the lower Note
Stage 2: Assign the transposed name to the upper(same note on the score)

Stage 3: Find the clef that names the note

The scale is given by the following sequence of clefs

C3 (Alto clef) F4 (Bass Clef)C2(Mezzo soprano clef) F3(Baritone clef) C1 (Soprano)C4 (tenor clef) G(treble clef) assigned to a given note

Transposition is a mere shifting of this sequence of clefs
Transposed C2 F3 C1 C4 G C3 F4
ROOT C3 F4 C2 F3 C1 C4 G
Interval 1 2 3 4 5 6 7