halldorophone - interview with creator Halldór Úlfarsson

The halldorophone is a unique acoustic-electric instrument created by Halldór Úlfarsson from Iceland. One of its leading players is Oscar-winning Hildur Guðnadóttir, who used it extensively on her score for Joker, and was part of its development. We talked to Halldór about the cello-like instrument and how it grew from his original idea to becoming a sought-after sound at the heart of tracks from the likes of experimental metal band Sunn O))) and psychedelic folk rap artists CryptoChrome. If you want to see it in action, Bill Thompson will be playing one at his Cafe Oto show in London, on Tuesday 25th February.

Halldor Ulfarsson, halldorophone - © Myrto Grigoriou

Inspired by art and circuit-bending

How have things been for you since Hildur Guðnadóttir won an Oscar for Joker, with your unique instrument a key part of the score

Intense. She has been gracious about mentioning where she uses the instrument in these high profile projects so on the back of her recent successes the halldorophone is getting loads of attention. Musicians are a curious lot and I am getting inquiries from all over at the moment, which is super nice…

What inspired the halldorophone originally, was it your own musical background

I don’t have a musical background. Well, debatably now, but no formal training playing an instrument. I am completely unable to think structurally about music, in terms of harmony or rhythm as I don´t have a concrete system of reference. I do however listen to a lot of music, love music, mostly hang out with musicians and am very opinionated about most things musical.

To answer your question though the halldorophone was originally inspired by the work of my friend, Norwegian artist, Atle Nielsen who I met when studying visual art in Finland. Atle is a cool artist who builds musical sculptures and installations. At the time he had a little circuit bent instrument with a feedback mechanism as the main control feature, that thing sounded very aggressive (and was affectionately dubbed the “fartmachine”) but the dynamics of the control schema really appealed to me and I had an insight that doing something similar with strings would be a more mellow way to work with the same dynamics. This led me down a fruitful path as it turned out. And really, string players have been using feedback in one way or another since we had electric guitars, so somewhat predictably there is material to work with. But the halldorophone is, perhaps special, as it is fundamentally configured around working with feedback and I keep asking: What makes sense when feedback is the whole point of the instrument? Which nudges it past “color” or “effect” towards being a method of approaching string playing.

What new sounds and sound combinations were you aiming to make possible

Well there was a particularly lively music scene in Helsinki when I was studying there at the Academy of Fine arts, lots of overlap between improvised experimental music, sound-art people and those getting a rigorous music education at the Sibelius academy. It was a fun time with lots of mixing and a permissive, experimentally minded atmosphere. Sound and musicality felt like something to experiment with alongside other available material and, like I allude to above, the first impulse was to make a system which “wants to go” all by itself, the dynamics of which I could then “ride”. The big thing for me being “to shape” rather than “decide” as I don’t have the sort of mental scaffolding to work with musical ideas. So this kind of system allowed me to be musical (to an extent) and active in the moment, reacting to the instrument and other people.

A sense of register, ergonomics and what I now consider the very interesting phenomena (beating, competing for prominence between the strings) which the halldorophone is good for exploring all came later. It took a while to realise how much material there is to investigate with an instrument configured in this way. As the project progressed I gradually gained an increased understanding and vocabulary to focus on different aspects of the system and its affordances.

First cello-like halldorophone in progress, TAIK Helsinki

Woodworking and dirty electronics

How did you make the first prototype and what challenges did you face

Depends how you are counting! Before the halldorophone became-cello like. There were some different configuration experiments. The very first sketch of this project was an acoustic guitar in such a condition that someone estimated it to have no value and gave it to me. I put a hammer through the back and plugged the hole with a speaker cone (scrounged together with an amplifier from a pair of computer speakers) which I hooked up to an electric guitar pickup. This thing served to confirm my suspicion there was fun to be had, and it got further mangled and reworked a few times before it eventually being left by the wayside somewhere… The biggest challenge with that thing were the electronics, they were very dirty and I didn’t have the skillset to troubleshoot them. Today I probably could have, although electronics are not my strong suit, I prefer to work with people who do audio electronics professionally when developing stuff for halldorophone.

Later, when I started to treat this as a design project and was thinking about an identity for an instrument organized around this principle of feedback the configuration of a cello came up. The first cello-ish halldorophone was made under the tutelage of renowned Finnish guitar maker Kari Nieminen. It was a serendipitous coincidence that he was teaching a half-year module in the product-design MA program I had enrolled in to up my design skills to develop the halldorophone. Luthiery is an interesting skillset which requires internalising a large body of tacit craft knowledge, one I greatly enjoy having and now look forward to refining further as this project is catching a favourable wind. But learning fine woodworking to the extent of building an acoustic-guitar soundbox was certainly a challenge at the time.

halldorophone soundboxes - CNC experiment

I did a residency at EMS (Elektronmusikstudion) in Stockholm where me and Daniel Araya experimented with developing a pickup based on a semiconductor chip. This was building on the work of a retired airspace engineer in the States (who’s name I forget), this guy had built something like that for his lap steel. We did not find this technology to be very suitable in terms of accurately representing string vibration, it was too sensitive in a very peculiar manner as it detected the string along a narrow beam which generated a truly remarkable phenomena when coupled with the feedback. The string would start to vibrate in a single plane (strings generally vibrate in three dimensional patterns). I still have that hardware and have thought to do a further study of this phenomena, perhaps as an installation rather than instrument..

In an ongoing collaboration with double bass player Adam Pultz (modifying a double bass in halldorophone-like ways) we have become interested in developing an optical pickup. As even the best, electro magnetic pickups will always display variant response based on distance to string (think fretting etc.). So we are hopeful to get some time with Dan Overholt at Aalborg University who has built such systems in the perhaps, and perhaps we will devote some time to develop optical pickups in coming years.

halldorophone experimental pickup, EMS Stockholm

Hildur Guðnadóttir and the sympathetic strings idea

Tell us about your system of sympathetic strings and electronics

Each string has its own pickup control setting for their volume in the main mix, either the onboard summing-mixer sliders or a send-return (usually to volume pedals). That is the significant part, good channel separation and the ability to trim each string. With a prominently accessible master volume for the final mix to the power amp.

I was chatting to cellist Judith Hamann who just visited here in Athens and was reminded that the sympathetic strings, kind of, were Hildur’s idea. Based on her first impressions of the first proper halldorophone (which had no sympathetic strings), she realised that some manner of “drone strings” would suit her playing. She was starting to form an opinion of how the instrument would be useful and there was a tension for her, between wanting to play the upper set in a fairly conventional way, but that fretting, bowing, plucking etc. would sometimes disturb delicate feedback stuff she had going on one or two strings at the same time. So, I can’t remember how articulate she was at first, but gradually the idea of the sympathetic set of strings came out of bouncing this sentiment back and forth.

A note on the electronics. There have been a few collaborators who have worked on the circuitry (preamps and mixing). The first set of pickups and preamps were made by Jonte Knif (of Knif Audio) who was then working out a tiny little basement storage space in Helsinki. He was already building the first of his super high end studio gear. Today Jonte’s equipment is in high demand and he is expanding into instruments (people should check out the Knifonium tube synthesizer) and Knif Rauman hi-fi speakers which are blowing peoples´ mind in terms of fidelity. Christian Zollner of Berlin based Koma Elektronik reworked Jonte’s circuit at some point when I started winding and packaging the pickups myself. Derek Holzer has had a hand in troubleshooting and refining the same circuit, but the weak point was always my pickups.

It is very pleasant to now be working with the Nu single string pickup made by Joel De Guzman at Cycfi Research. The Nus are very clean and consistent and finally feel like a solution which it is worth re-designing the whole system around so I am collaborating with a greek engineer, Orfeas Moraitis who is reworking the circuitry, including a power amp! But dealing with generic, off the shelf power amps has been seriously inconsistent and a major paine so we are going for our own. The electronics-future is bright.

2015 halldorophone

There are five instruments in existence so far, each unique, what special features do they have

Yes they are all unique, there is always some experimentation with configuration, material and method. Ergonomic and control tweaks have been around connectivity, for example how much to break out to external volume control (pedals for the sympathetic strings). Two or four sympathetic strings has been something I have been debating (verdict is still out).

And there is a particularly daunting feature, the vibrato levers for each string (whammy-bar-ish type deal) I have been experimenting with, I have tried versions of this for the upper set of strings (sitting at the top of the neck) and the sympathetic strings (clumsily accessible to the thumb of the left hand). Opinions vary greatly on the usefulness of this but players who get into them (for the upper set) identify that this tensioning allows for modulating the feedback without the dampening effect of fretting. Some players have developed another method of reaching down and bending the strings below the bridge to a similar effect, but ergonomically perhaps a little awkward. The mechanics of the levers need further engineering and I will keep working on them but my instinct is to not include them on every instrument moving forward. They really need to be refined function as intended and even then some players just don’t see the point (Hildur for example specifically requested not to have them on her instrument).

2012 halldorophone, study for sympathetic strings EMS Stockholm

There is powerful video of Hildur Guðnadóttir playing the instrument, tell us more about her role in the development process

For sure. There were two significant conversations on either side of deciding on the “cello-ish” configuration. Before, there was an over time conversation with my friend, composer Tim Page who took the early sketches (kind of) seriously and indulged me in debates about what would be an appropriate packaging for such an instrument. Tim was a big part of coming to an informed decision to make it cello-like. But a while after that, Hildur was the only one giving meaningful feedback on what worked well or not.

That video you mentioned (Composition for halldorophone #5) hails back to a time when I was still doing projects as a visual artist and when I predominantly thought of the halldorophone as a narrative prop. I was pretty confident that string-based feedback was too thin a premise to warrant a discrete (individualised) instrument with any kind of generalisable musical usefulness. But there was a strong interest in the project, which I put down to the idea of a new instrument being a quaint curiosity and, as consequence, good narrative material for a visual artist. Hildur had the instrument for a while before that project, she had gotten familiar with it and brought that to her composition and performance. The work is basically two live concerts of her performing her for a live audience in an artist studio complex and the hall where the danish queen throws her christmas party. The work is these two concerts spliced into one piece.

2015 halldorophone

You developed the instrument at the Experimental Music Technologies Lab at the University of Sussex. What helped you on that journey, and what is the Lab like

The first halldorophone was ready in 2008 and came out of my studies in Helsinki, Finland: first the Academy of Fine Arts and then an MFA in design (at what is now Aalto University) where my graduation piece was a halldorophone (which is still in use and incidentally in Finland at the moment, with composer/cellist Max Lilja).

I joined Emute tentatively in 2016 when I started collaborating with Alice Eldridge and Chris Kiefer on a project modifying cellos (somewhat inspired by halldorophones). But I became a member in 2017 when I started my PhD at Sussex with Thor Magnusson and Chris Kiefer.

Being a member of the Emute Lab is quite significant as it is the first time I (and the halldorophone) are formally part of a music technology research team, and this has expanded my thinking in various ways. One very significant understanding is how fluid musical instruments truly are. We do have some very stable patterns over time (like the cello and piano for example) but instruments continuously take on and shed features based on trends in material culture, musicality, manufacturing and technological innovation. So in some real way it is a confidence builder, understanding that mixing up existing technologies and methods to amplify a particular affordance is very much in line with the history and tradition of instrument making so far.

The Emute lab and group is great and there are some very exciting research projects going on, perhaps most notably at the moment: MIMIC, a web platform for the artistic exploration of musical machine learning and machine listening. But also stuff on acoustic ecology, organology, sonfication strategies, hardware development and new performance practices. Most significantly there is a true culture of interdisciplinarity at the lab, people generally have a strong footing in other disciplines than music (philosophy, computer science, literature) which they bring to the work, keeping things fresh. It is a very stimulating environment.

What kind of players and composers are using the halldorophone

Well it is a wide range of people, curiosity and a desire for exploration being the common denominator. Composers range from the self taught to trained in the western classical tradition, with all kinds of players: Guitarists, piano, double bass who have done stuff with halldorophone. But users who have, or are likely to, grow into using the instrument as a significant part of their expression is emerging as: cellists, who are into electronic music and compose and perform their own music. If there is a “halldorophone-type” this would probably be it…

How do cello players adapt to the halldorophone, is it a steep learning curve or have you worked to make it easy to use

Well, the ergonomic layout is close enough that a cellist can recycle their skillset without too much adjustment. The acoustic of a halldorophone (with electronics off) are very different to a cello, kind of like a nasal lute, and probably not attractive to many players. But with the feedback going it is a fundamentally different instrument. As the halldorophone is continuously injecting vibrational energy into itself, there is a resistance, almost like a second player to contend with.

So accepting the premise of the instrument is to enter into a relational style of music making, where the dynamics of the tool need to be actively negotiated and navigated. So if you abandon ideas of absolute control and resign yourself to a “conversation” with the system to explore and express musical thought you will probably be more satisfied than if you attempt a more conventional approach of instrument mastery.

Experimenting with the Bela platform

You are using both analog electronics and also working with the Bela board. What results do the different components give you

Well! Relating to the above. Since early days of this project the odd user (mostly classically trained composers) have requested features to make the instrument more controllable, some notch filtering etc. to make the feedback more like a stable and predictable sustain feature. I have resisted as it has not felt like the most interesting trajectory for this project (the “uncontrol” being more fun), but now that the instruments has a somewhat stable identity and already a performance practice based on its “traditional” setup I find it interesting to open it up.

Starting the PhD with Thor and Chris was also a perfect opportunity to do something a bit challenging and I made two instruments to use for the research, the bela-halldorophone being one of those.

The way I have developed halldorophones is to lend them to interested (and interesting) musicians who use them for a while and then report back. This has been the main method to figure out what people use it for and, consequently what to refine and work on further. Now with Bela on board I’m doing the same thing, and curiously waiting to see what the users do with it. Fully expecting that some people might create more manageable conditions (from a conventional point of view). The Bela is super cool for this research and the instrument in question will go on to live at Emute Lab (University of Sussex) once my research is completed (where curious souls can potentially negotiate access to it).

2019 halldorophone, now with Bela onboard

Evolving design

The design ranges from a version that looks traditional through to one that looks very sci fi. What aesthetics are you aiming for

Well I’m experimenting with materials and style. I don’t really like to be too concrete. I don’t know what a halldorophone should look like. Or rather I don’t want to give the impression there is a way it “should” look. Think guitar, electric, acoustic, hollowbody, gipsy whatever. The guitar is a pattern, a material pattern, an ergonomic pattern, a pattern for certain kind of use, an object to do a certain kind of thinking through. It is ownerless and freely interpreted worldwide, it belongs to our cultural commons. This is the best possible fate for a musical instrument, to be adopted, remixed, reworked, copied, pasted by anyone interested. It becomes a viable “species”. As much as there is a design strategy for halldorophones, that possibility is always present at the back of my mind and as I experiment with methods and materials I drop little hints that this instrument is not fully stabilized, there is room for interpretation. In fact I have a large scale project in the works which is intentionally organized in such a way as to entice some instrument makers to “steal” and copy halldorophones. But this is still a secret ploy…

What are your plans for the halldorophone this year

Some exciting prospects. There are a couple of commissions in the works which are allowing me to finish building my workshop here in Athens. Welsh producer and multi instrumentalist Leon West (Secondson) is getting his very own, custom halldorophone delivered. And a couple of feelers for more which we will see how pan out. Also some research projects on an ongoing basis, I have become interested in the IKO 3D speaker by Sonible. Me and London based cellist Nicole Robson are hoping to work with that in coming months. Getting my first intern (icelandic product designer) and looks like I will be collaborating with a UK based student of luthiery to build their interpretation of a halldorophone. Loads of stuff cooking!

  • You can find out more on the halldorophone website or on Facebook, and listen to Hildur Guðnadóttir playing halldorophone on this Sunn O))) track Novae below. She also plays it on the Arrival film score in her collaboration with the late Jóhann Jóhannsson.