Foundational Drone: A Sonorous Base
Foundational drone defines the tonal/modal space by establishing one pitch as its reference point. Especially in the case of tonal music, foundational drone is often on the tonic pitch (in non-tonal music, foundational drone becomes the tone-center). The fundamental difference from the T-pedal at the beginning model is that the harmony does not have strong functional connotations, and that the drone does not incite local expectations. On the other side, the major difference from folk drone model is in the character of its sound, and the character of the melody above it.
Foundational drone is a source of harmonics, and as such it is a sonorous base of the piece. The Indian drone-instrument tanpura, for example, uses very thin metal strings and the projection of the harmonics is further enhanced by placing tufts of wool or silk at certain points between the strings and the main bridge.The physical interaction of the tones of the melody with the tones and harmonics of the drone produce different levels of consonance and dissonance. For the connoisseur of Indian music, the drone has also a strong modal working, as it helps establishing the raga.
Dagar Brothers, Asavari
In Western art music, non-harmonic foundational drones could be found in early music. Improvising a melody above the very augmented notes of a cantus firmus could be felt as exploration of the sonorous realm created by the harmonics of the drones. Drones would in this case be the individual tones of the cantus firmus. Especially when the second voice is improvised, the singer focusses on the resulting sound between his voice and the sustained sound in the other voice. Each new long note opens the new space for exploration. Each new sustained tone is a local foundational drone. An example of composed version is Leoninus’ florid organum Haec dies quam fecit Dominus.
Vocal drones in folk music of North Caucasia region are, in this context, similar to the previous example. The double-drone moves in the course of the piece, which for a contemporary western listener could be felt as a sort of harmonic accompaniment (the example is taken from The Garland Encyclopedia of World Music, Vol. 8: 857):
In Frescobaldi’s Toccata sesta (libro 2), the notes scored for the organ pedal are held very long, throughout the whole sections. The pitch progression of the pedal is moving in the rightward direction of the circle of fifths (F - C - G - D). The harmonic progression is however plagal (IV -I). Each pedal tone is the tonic of the current key (major or minor). The modulation to the key of the next pedal-tone takes place before the arrival of the new tonic in the bass. This means that the F in the bass ends as being the subdominant in the new key, C major, even before the new bass tone sounds.
The very long duration of each pedal tone is the base for rather improvisatory material of the voices above it. The voices (variable number of them) expose, next to not-very-profiled meditative fragments, also short motifs and scalar passages, which are often imitated on different pitch and in several voices. The harmonies suggested by the melodic parts are mostly consonant with the pedal tone, although there are many embellishing dissonances (some chromatic). The F sounds under F-major, D-minor, Bb-major, and F7 (implied) chords. The first prominent melodic figure (m.2) is imitated on all the four pitches that are consonant with the pedal tone.
Although each pedal is clearly the tonic, most of them are not felt as harmonic pedals. There are probably two main reasons for this: 1) the non-directive harmonic progression, and 2) the rather floating sense of the meter. The essence of a harmonic pedal is the conflict between progressing harmonies and the bass that does not progress in the same direction. In Frescobaldi’s toccata, the harmonic context does not make the listener perceive two independent harmonic layers, but rather two independent textural layers. The ‘consonant nature’ of this pedal incites neither concrete expectations, nor harmonic tensions. The pedal provides sonorous foundation for florid play of the melodic voices. Any pitch other than the tonic would be less suitable for this.
The tonic-ness of the pedal is, nevertheless, to a certain extent reinforced by the simple fact that it is a pedal. Although most of the chords are F major chords, the D-minor chord in m.3 would, without the pedal, have potential of being felt as a local tonic. The pedal contributes to anchoring the harmonies to F. It also colors them in this way. The appearance of Eb in m.9 creates the secondary dominant without disturbing the tonic-ness of F. The only moment when F changes its harmonic identity is in m.10, where several actors transform the pedal from foundational sound into dynamic harmonic function. The melodic line in the top voice, in combination with the melodic line (especially the last beat) of the lower voice, incite the expectation of the C-E third, and the C major chord. The harmony in m.10 so becomes the subdominant with sixte ajoutee, and the bass tone F is for the first time expected to resolve. A cooperative interaction between the melodic voices toward the C-major chord results in perception of the conflict between the bass tone and the anticipated resolution - the conflict that incites the expectation of the change in the pedal. Interestingly, at this moment the bass tone feels as a long harmonic bass, rather than the pedal tone that have been sounding already for ten bars. The cadential resolution in m.11 will bring new tonic, supported by the new pedal tone - the new cycle may begin.
Foundational drones (such as those by Frescobaldi) are often pitched low. In folk music, some drone-instruments are designed as extremely long to achieve the deep sound, e.g. the sixteen-foot Tibetan trumpets or an Egyptian reed pipe more than five feet long. The property of low fundamental tones is a better audibility of its individual partials.
Although the pedal tones in Frescobaldi toccata already from the first bar have a prominent place in the texture of the piece, this fact becomes even more obvious when the listener understands them as being foundational drones. Understanding them as such creates a particular aural frame (context), in which the ears additionally tune to texture and sound quality.
The score of Bach’s Toccata & Fugue for organ in F major (BWV 540) looks similar to that of Frescobaldi. It is however perceived as different in sort. Pedal Story 'Harmonic pedal or foundational drone?' reflects on this piece.
The double drone in Arvo Pärt’s Fratres for string quartet is realized as sustained fifth in the violin part, and occasionally doubled octave lower, by Vcl. The opening section of Fratres is placed in the middle-high and high register. The thin texture consists of the drones and the three melodic lines realized by flageolets above the drone (two voices in parallel thirds, and the third moving between the notes of the ‘tonic’ chord)
The drones are reinforcing the hierarchy in the pitch-space. Although even without the drones, G-D fifth occupies the central position (the parallel voices are moving in gradually increasing length away from its center B, and in the mirrored way returning to it), its harmonic meaning could have been perceived differently without the drones. The tone collection of the melodic voices (G-Ab-B-C-D-Eb-F) could have projected the feeling of C minor key, resulting in the feeling that what we hear is the dominant. The cooperation of the drones and the ‘tintinnabuli’ voice (playing G-minor triad) results in attributing stability to the pitch G, and assuring its ‘tonic’ function. The modal chord progression is accommodating this aural interpretation. Fratres is a set of variations, where each variation has different central pitch. The tone collection also changes, which renders some beautiful sonorities. The stable foundational drones keep the original ‘tonic’ as the reference point throughout.
Foundational drones create space for other voices. In music based on slow harmonic rhythm (or no harmonic progression) the melodic voices are free to flourish. In modal jazz, for example, the melodic material is accompanied with static chords and pedal tones. One of the great examples is John Coltrane’s song Olé (1961), featuring two bass players to hypnotic effect, with b pedal sounding throughout (18 minutes). His better known My Favorite Things is built on the foundation of chordal ostinatos on piano that sound over and over again, above the pedal e in the bass (transcription by Ingrid Monson (1996: 112)):
Sonorous Center As A Conceptual Variant Of Foundational Drone
In non-tonal music, a pedal tone can work as an anchoring factor, centralizing the tone system by giving a special status to the pedal-pitch. A variant of it could be note-nucleus, although neither of the two can have the same function as the tonic in tonal music. In his textbook on 20th century music, Kostka (2006: 109) writes: “Pitch-centric music, whether tertian or nontertian, has had to rely on methods other than the V7 - I progression for establishing a tonality. These methods include such devices as pedal point and ostinato, accent (metric, agogic, or dynamic) and formal placement.”
In Debussy’s Voiles, the pedal tone organizes an otherwise non-profiled whole-tone collection. The piece consists of five sections, four of which are entirely hexatonic: Ab-Bb-C-D-E-F#. The perfect equality of all the intervals does not suggest any hierarchy in the collection. The repetition of the opening motif could mark the first third (E-G#) as a recurring element (the listener would probably recognize it if the motif was repeated one more time), thereby assigning more weight to it. However, at the moment the bass enters with the Bb that will be present almost constantly in this piece, this pitch becomes a very powerful anchor in the tone-space. Other pitches relate to it, which centralizes the system and organizes it hierarchically. As each pitch has different relation to Bb, each of them acquires an identity in the system. Even if these identities are not clearly discernable, the pedal tone has created a context. The piece is not exactly ‘in Bb’, but it certainly is ‘on Bb’.
Apart from this ‘tonicizing’ effect, the pedal tone Bb certainly has its sound qualities. It is played in the low register where other voices are not present. Thereby, it represents this low register. It does have quality of a textural drone - the model that will be explained in the following chapter. The pedal of Voiles is an active element in forming the structure: its rhythmic pattern is different in each section.
One of the more ‘extreme’ cases is Webern’s string quartet op.5/iii. The pedal tone C# puts extra weight on this pitch, and in a way, promotes it into the one with special status. The piece begins with pedal-ostinato on this tone, and also finishes with it, in a unison - which could be understood as a gesture of tonal rounding off.
next: Textural Drone or return to menu.
 Erickson 1975: 103-104.
 “The continuous sounding of one or more notes provides the harmonic base for the performance. This not only clarifies the scale structure, but actually makes it possible to develop amazingly complex modes.” (David Courtney on http://www.chandrakantha.com/articles/indian_music/drone.html)
 Van der Merwe argues that the ‘drone-mania’ (he refers to long notes in early Western polyphony) was important seed for the development of harmonic thinking. According to Van der Merwe, the origins of tonal harmony could be traced back to shifting drones. (2004: 64-65).
 For more information see Erickson 1975: 103-104.
 The resulting mode becomes Phrygian with major third.
 Jazz scholar Barry Kernfeld (1995: 67) writes: “This slower rate [of chord changes] is achieved through the use of drones or of weakly functional successions of two or more oscillating chords. In the sense that this slowing down involves the weakening of functionality, the resulting music might be called modal rather than tonal.”
 Related to the ‘tonic-ness’ of Bb pedal, one thing is curious: not only that it stops before the end of the composition (which could be put in the relation to the beginning, also without Bb pedal), there is another sustained pitch in the last bars, F#(!).