Lesson Objectives:
To understand the relationship between keys in the B section
To understand what the variant of the fugue subject is
To understand the exchanges between the concertino episodes and the ripieno know as ritornello form
To understand what a sequence and dialogue are
To understand what a canon and a suspension is
B Section Tonality
In the B section the music modulates to the relative minor—B minor and then modulates through a number of related keys reinforced with the use of a tonic pedal
The important thing to remember is that all the keys relate to each other. They are not just random choices!
The important thing is the B section modulates from the tonic D major (the key the piece is in) to the relative minor – B minor. It is called the relative because it shares the same key signature (2 sharps)
Ritornello Form
The B section consists of a number of episodes (sections) based on a version of the subject (variant)
These alternate with short passages from the ripieno (orchestra) which recall the opening fugue subject.
This structure of episodes and short returns of the A section is called ritornello.
Difference between A and B sections
Mostly uses a minor tonality (B minor)
The texture is generally thinner with not so many different musical lines being played at the same time.
There is dialogue between the solo instruments
The ritornello exchanges between the concertino playing the episodes and the ripieno playing the music from the opening subject creates an antiphonal texture
The solo concertino instruments take on a more prominent role
Variant
Sequences
Melodic sequences are used throughout the movement. There is also much musical dialogue (like a conversation) between the three solo concertino instruments.
Below is an example that shows both these perfectly!
More Sequences
Another example of a long sequence follows for the solo harpsichord, which also shows how Bach gives the harpsichord more of a solo role in the B section.
Remember: The harpsichord takes on a dual role in this piece as part of the accompanying continuo and as one of the three solo instruments.
Texture
When we talk about texture, we are talking about how the different musical lines (instruments) are put together and layered.
Is there an instrument playing alone? = monophonic
Are there two different equal lines playing at the same time? = contrapuntal
Are there a number of instruments playing the same thing? = unison
As we’ve already noted, the texture throughout most of this movement is contrapuntal though we have also noted the opening 2 bar monophonic texture and the lighter dialogue texture between instruments in the B section.
There are other textural changes worth noting.
One of these is a canon between the right and left hand of the harpsichord.
A canon is like a round where both parts are the same but with one part starting after the other.
Canon is the same melody started at different times.
Compare this to the unison texture at bar 130 where both instruments are playing the same thing at the same time.
Diatonic Harmony
The harmony throughout this piece is made up of simple chords, mainly triads, in root position or first inversion.
This is called diatonic harmony as the chords only contain notes from the scale the music is in. They are also mainly simple triads. Very different to pieces composed later such as ‘Defying Gravity’ or Star Wars’
Suspensions
Bach makes use of suspensions.
This is when a note is held (or suspended) from a previous chord to a new chord to produce an expressive ‘clash’ before moving to the new chord.
A ‘clash’ is when notes don’t fit together, or sound ‘good’. Next door notes like tones and semitones (A and B or A and A#)
They are beautiful!!
Review Questions
1) Identify the tonality of the B section
2) Name the keys modulated to in the B section
3) Describe how ritornello form is used in the B section
4) Describe what the variant of the fugue subject is and how it differs from the subject
5) Describe what a sequence is and give an example of where it can be heard
6) Describe what is meant by a dialogue between instruments
7) Name the instrument that plays a canon
8) What is meant by a suspension?