Understanding the Tonal Answer

• The melodic structure of the fugue subject must
establish the key clearly.
• Therefore, many fugue subjects emphasize members
of the tonic triad, particularly ^1 and ^5.
• A fugue subject often contains a rhythmic or
melodic characteristic (or both) that makes it easy
to hear later in the piece.

• This restatement is almost always in the dominant
key (V or v) and takes one of two forms:
• An exac transposition into the dominant key, called a real
answer.
• A transposed version in the dominant key that contains
one or more slight alterations, called a tonal answer.

• First, if given a fugue subject to which you will
write an answer, you will learn whether the subject
requires a tonal answer, and
• Second, if you need to write a tonal answer, you
will learn how to make the correct stylistic
alterations to the answer.

• Why do composers use tonal answers? Why not
simply transpose the answer to the dominant and be
done with it?
• To begin to understand these questions, let’s start
with a typical fugue subject.

• Here is J. S. Bach’s subject to the Art of Fugue. As
with most subjects, the tonic harmony is established
right at the outset.

• Now here is a real answer to the above subject. The
subject is simply transposed to the (minor)
dominant key.

In actual practice, the answer enters when the subject
reaches its final note:

• But there’s a problem: when the answer enters in m.
5 the underlying harmony at that point is D minor,
which is no surprise since the subject ends on ^1.
The changes to a minor in the following measure.
• The answer’s second note, E, clashes with this tonic
harmony:

• Change the subject’s ending harmony (thus
destroying the sense of tonic associated with the
ending of the subject)? Or,
• Alter the answer to accommodate the harmony?
Composers opted for the second option:

• Note that we had to change only ONE note of the
answer to accommodate the underlying harmony.
(This is the solution that Bach uses, by the way.)

Assume that a fugue subject will take a real answer
unless one of the following three conditions exist:
1. The subject begins on ^5 and does not modulate.
2. ^1 and ^5 occur very close to one another at the
outset of the subject (very often the first two notes)
and the subject do not modulate. Or,
3. The subject modulates to the dominant.

• Answers to these type of subjects usually require
only a single alteration: start the answer on ^1 and
transpose the rest of the subject to the dominant key.
• Consider this subject by J. G. Walther (J. S. Bach’s
uncle):

• The subject starts on ^5, so we begin the answer on ^1.
(Although there are three eighth notes on ^5, they
represent a single pitch, so we change all of the
corresponding notes to ^1. )
• Then transpose the remainder of the subject up a P5.

• These are a very common type of subject: the
subject starts on ^1 and then leaps to ^5.
• Usually only one alteration is necessary: answer ^5
with ^1. Thus, if the subject begins ^1ÿ^5, the answer
begins ^5ÿ^1.
• Write the rest of the answer up a P5.

• Consider the fugue subject by Bach:

• ^1 at the opening of the subject is answered
by ^5.
• ^5 at the opening of the subject is answered
by ^1.
Although set in the dominant key, the answer is
initially harmonized with the tonic chord of the
home key, not the tonic key of the dominant. The
exchange of ^1 and ^5 remains in place as long as the
home key tonic is the underlying harmony.

• Modulating fugue subjects are uncommon
• The new key is always V.
• The answer MUST modulate back to I (i), because
to allow the answer to modulate up to its dominant
is unacceptable so early in the fugue (C Å G Å D?).
• At some point, the answer is transposed up only a
P4 instead of a P5 (C Å G Å C).
• There is no definite formula for answering
modulating fugue subjects that works in all cases.

Charles Nalden (Fugal Answer, 1969) groups fugue
subjects into three melodic types, which determine
where the P4 transposition will occur:
1. Subjects whose opening is marked with a
prominently placed ^1 and ^5.
2. Subjects whose melodic line is marked by a
division (usually a rest or implied cadence).
3. Subjects with an ‘indivisible’ or ‘unyielding’ melodic
line.

• The alteration takes place at the beginning of the
answer. Once the typical exchange of ^1 and ^5 takes
place, transpose the rest of the answer up a 4 th .
• Consider this subject:

• Simply make the exchange of ^1 and ^5 and then
transpose the rest of the subject up a P4. (Note that
the use of ^1 in the answer already represents
transposition by P4 anyway.)

• In the actual context it sounds:

• Look for a rest or implied ‘cadence’ (on the tonic
chord).
• The alteration takes place immediately after this
point.
In this first example, the change takes place near the
beginning of the subject, following the eighth rest.