Musical conventions in Western Europe were gradually evolving from modal harmony to a system of major and minor tonality that became common practice in the Baroque period. The core dominant–tonic functions were established, and secondary dominant chords were used. There was more vertical awareness, and while the music remained consonant on the whole, dissonances and non-chord tones were used more freely. Musica Ficta was falling out of favor, as notes that were consistently altered in performance became part of the key signature or accidentals were notated. The melodic minor scale was used in all parts, with raised ascending 6th and 7th scale degrees.
The practice of adding figures beneath the bass line as a form of shorthand for accompanists to “realize” was developed in early in the 17th century. The continuo concept, which involved the use of a chordal instrument, was applied to many types of music. The Keyboard instrument most often used was a harpsichord, also known as a cembalo. Alternative instruments were the lute or a small organ. Continuo players were skilled at improvising harmonies to support vocalists and instrumentalists using the figured bass symbols in the same way Jazz performers are skilled at reading lead sheets.
In general, the figured bass numbers are placed below the bass to identify the intervals to be played above the bass note. If the bass note is the root of a triad, no figure is added, and the 3rd and 5th above the root are assumed to be present. This avoids redundant “5/3” numbers under all root position triads. If the bass note is the 3rd of a triad, a 3rd above the bass note is assumed, and only the number “6” is added. This avoids redundant “6/3” numbers. If the bass note of a triad is the 5th, the numbers “6/4” are both added to identify both intervals above the bass note.
Figured bass is still in use today to identify harmonic structures. The convention now is to add it to Roman Numerals in analysis, but in the 17th century vertical structures were not identified by function. Roman numerals were first proposed by Johann Kirnberger in his treatise Die Kunst des reinen Satzes in 1774. Gottfried Weber introduced the use of upper case for major chords, lower case for minors, and the diminished symbol around 1820 in his Theory of Musical Composition. For a more complete explanation of how to interpret figured bass symbols, see Figured Bass Symbols in the materials below.
The foundation of continuous variations is a repeated bass line or chord progression in a continuous flow, with melodic, rhythmic, and textural elements varied in each iteration. This form of composition was widely used in the 16th century and continued to be a popular vehicle in the 17th century. Any basso ostinato type of composition may be called a chaconne, a passacaglia, or in England simply a ground. These terms were used interchangeably.
Examine the examples of ostinato variations in the materials below. The Purcell piece, A Ground in Gamut, uses the bass line G-F#-E-D-B-C-D-G. This was a very popular ostinato pattern that J. S. Bach also used in his Goldberg Variations. The Couperin Passacaille ostinato pattern is just four notes, the descending scale degrees 8-7-6-5. The first section is in G minor, and the second section is in G major. Both composers exhibit tremendous ingenuity in creating interesting music over a simple repeated sequence.
Also a popular form in the 17th century, the trio sonata employed two treble clef instruments with a basso continuo. The upper parts were highly imitative, and often crossed each other. Sequencing of motives and phrases was a favorite developmental technique. Dissonances became commonplace, particularly appoggiaturas and suspensions.
Examine the example of Corelli’s Trio Sonata Op. 4, No. 1 in the materials. The characteristics mentioned above are obvious. It is also a good example of the chamber suite, comprised of dance movements. In the Largo Prelude we see the bass part joining actively in the texture as it did increasingly as the 17th century progressed. In the Allegro Corrente, the bass interacts sequentially with the violins. The music is a typical linting dance in triple meter, with an Adagio section at the end. The Presto Allemanda gives the bass instrument independent running lines under held notes in the violins. Corelli also wrote many trio sonatas without continuo, but with three parts that were equal and usually performed on recorders.
There were several popular types of imitative instrumental music in the late 16th and early 17th centuries. The instrumental canzona was derived from the French chanson, called a canzona francese in Italy, and was written for both keyboard and ensembles. With a single theme treated in a polyphonic fashion, this was an ancestor of the fugue.
The ricercar had many similar characteristics, with themes treated in the manner of a fugue and developmental techniques applied. In England, the fantasia was another type of imitative instrumental work which foreshadowed the fugue.
Analyze the canzona and the fantasia by Girolama Frescobaldi (1583-1643) in the Materials below to see how this early master laid the foundation for contrapuntal keyboard works in the next century. They have an exposition of the subject(s) stated by each voice in succession. If the answer that follows each subject has the exact same interval content, it is a real response. If the intervals are altered to fit a new key area, it is a tonal response. The entrances of the voices in a fugue generally alternate between high and low parts. The two high parts are the Soprano and Tenor, and the two low parts are the Alto and Bass. Examples of this would be S-A-T-B or A-S-B-T in order.
After the exposition, the parts undergo various types of development. Sequencing all or part of the subject with free counterpoint is very common, and imitation between parts is maintained. If a figure is used frequently as counterpoint to the subject, it is a countersubject. Overlapping entries in two or more parts is called stretto. The harmonic flavor is decidedly moving toward modern tonality, and more daring dissonances are showing up. There is more frequent modulation, and vacillation between related major and minor keys. In the final closing section of the fugue, the subject returns in the original key. These features are all seen in Frescobali’s “Canzona Terza.”