Expanding horizons – Improvisational explorations of 20th-century classical music by Peter Knudsen

"Expanding horizons" is an Artistic research project carried out between 2021 (August) and 2024 (November) at NTNU, Trondheim. The objectives were to contribute to knowledge on how different kinds of departure points can be useful for musicians when approaching 20th-century Western classical music through improvisation, an understanding of how one can navigate and negotiate the musical language of this repertoire, and insights into how the tension between different performance values can be navigated in this process. The research questions were: When applying improvisation to works of 20th-century classical music, 1. What role does the choice and preparation of musical representations play? 2. How can we navigate and negotiate musical structures such as melody, harmony and form? 3. How can we navigate the tension between fidelity to the work and creative expression? Based on selected pieces from this repertoire and practical explorations together with participating musicians, various approaches to creating improvisational frameworks were then explored. These included a wide range of scores, including lead sheets and indeterminate notation, as well as ear-based methods. From the perspective of integrating improvisation into the performances, approaches such as repeating elements, working with layers, creating transitions, and introducing open sections were examined. A key point was to use melodic material as a way of building strong connections with the source material, rather than relying on harmonic representations of the music. In terms of balancing respect for the original work with creative freedom, a “healthy dose of disrespect” pervaded much of the explorations, allowing deviations from the originals when they were musically justified. Throughout the work processes, an idea of focal points emerged, as aspects to focus on when reworking a classical work into an improvisational version. These focal points included the score, historical and performative contexts, expressive qualities, and the improviser’s personal voice.

Approaching harmony

Improvisation based on harmonic progressions typically involved a layer of interpretation, since the source material wasn’t written out with harmonic analysis. This led me to write out chord symbols for a large part of the repertoire, to facilitate the processes of improvising over the music. When doing so, I was aware of the fact that it imposed my interpretations of the harmony, which made me open to the possibility that passages might be re-negotiated at a later point.

These processes are described under the headlines interpreting harmony and re-interpreting harmony.

Interpreting harmony

The process of making the chord analysis often played an important part in the process of developing an understanding for the harmonic aspects of the music. It could also be quite challenging; taking a passage such as the following – from Hindemith’s Ludus Tonalis, Fugue in Eb – we are faced with several choices for how to interpret the harmony:

Figure 9.9. Fugue in Eb from Ludus Tonalis (Hindemith, 1943), mm. 1-20.

The first challenge is the lack of harmonic information, particularly in the beginning. Since we’re dealing with a fugue that goes from one to three voices, the starting passage requires us to make several assumptions based on the pitches at hand.

Another challenge is that some passages contain so much linear movement – often chromatically – that it is difficult to pinpoint what the harmonic essence might be in some places; vertical structures aren’t established in an unambiguous way. These factors can thus yield several interpretations, depending on the desired harmonic rhythm, the perceived tonal centers, and the amount of details one wanted to preserve.

To illustrate, two interpretations are written out below reflecting two approaches with different levels of fidelity towards the written passage:

1. Interpretation with high degree of detail
2. Freer interpretation

Figure 9.10. Harmonic interpretation of Fugue in Eb, mm. 9-12.

It should be noted that not even the first type interpretation is a 100% literal representation of the passage, given the limitations of chord analysis for conveying linear passages such as this one. While there are ways of writing out further details – e.g. indicating incomplete triads with added information such as (omit 3) – relying on such additions can lead to contrived symbols of limited usability for the performers.

In the freer interpretation, functional relationships and temporary tonal centers are reinforced. The type of interpretation that I used for Ludus Tonalis mainly follows this approach, sometimes as a middle ground between the two different approaches presented here. This was partly based on combinations of the pitches present in a given passage, the perceived harmonic gravity – what I heard when playing the music repeatedly – and an idea of what would be effective from an improvisational standpoint. There was also a certain amount of musical logic involved; in the passage above, the left-hand part is playing an imitation of the theme, the subject of the fugue. Hence, it might not be necessary to interpret the long notes on the accentuated beats as roots of an underlying chord. Also, knowing that the same theme in repeated in different transpositions throughout the fugue led me to examine other passages where it appears, such as this one (mm. 43-44), which reinforced my interpretation of Eb minor and Ab minor in the first two bars:

Figure 9.11. Fugue in Eb, mm. 43-44.

This is still not unambiguous, however, seen that there is an Fb in the second measure which implies a change in the harmony. A similar problem occurs when turning to other passages, which have other types of deviations.

It was important that the chord symbols should be there as a guide, and as such contain the essence of the harmonic movements, not all of the details. The balance here was to preserve the essential harmonic movements that gave the piece their particular character, without overloading the performers with too much information. Thinking this way also made it easier to remove some of the chord symbols I had initially put there, knowing that we could always choose to pick up things outside of the chords anyway.

Below is a recording of a harmonic interpretation of the entire passage with improvisations by myself and Krister Andersson, clarinet.

Recording 9.18. Improvisation based on Fugue in Eb, Andersson & Knudsen. Recorded at Kulturcentrum, Sandviken, 2022-02-27.

Although the aid of chord analysis in this case helped to give us a way in to improvising over the music, it can be pointed out that the character is somewhat different to Hindemith's original. This may relate to this way of interpreting the chords, as it makes the harmony sound more functional. The harmonization with a major third (G) in the bass in the first two bars might contribute to this, which reflects how I initially heard this passage, as a result of the pitch G appearing in the third measure. But it doesn't create the same ambiguity that is there in the original, which is a general challenge with using chord analysis.

Re-interpreting harmony

After having created harmonic progressions, it was common that the initial progressions were modified somewhat. The main reasons for this was that I – or other musicians – wanted to further emphasize harmonic details of the original, reinforce harmonic contours related to tension/release, or decrease the amount of harmonic information.

Sometimes, I also did slight adaptions to reflect changes in the form, particularly when there was a chorus-based form of improvisation. In Cortège, since we were repeating an overall form of ABA’, without the ending, it felt more justified to move back to the tonic chord rather than the diminished chord of the original.

Original version (with my initial interpretation of the harmony):

Figure 9.12. Cortège (Boulanger, 1918), mm. 62-68. Original piano version with added chord analysis.

New version:

Figure 9.13. Cortège, mm. 62-69, adapted version.

In the re-created version, there are still chromatically ascending lines that are preserved from the original, as parts of triads that strive upwards towards the tonic. The new harmonization still felt compatible with the musical language of the piece; in fact, this way of harmonizing passages – with triads that move upwards chromatically over a pedal point – is a device that Boulanger uses herself in other compositions, including Reflets.

After having improvised over this passage during a couple of performances, as the ending of the solo chorus, I added an optional loop for improvisers to extend the ending of the solo:

Figure 9.14. Ending of solo section for Cortège, optional loop.

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Peter Knudsen - Expanding horizons – Improvisational explorations of 20th-century classical music - 2025