Monochord Therapy

The single-string monochord

The Whipple Museum of the History of Science at the University of Cambridge describes the monochord as an instrument invented in Greece around 500 BC, with a string stretched over a hollow body and a movable bridge that divides it into two sounding lengths. Pythagoras is traditionally credited with showing that simple string-length ratios correspond to consonant intervals, such as 2:1 for the octave and 3:2 for the fifth, although the museum presents this attribution as tradition.

The same source reports later uses in medieval chant teaching, where Guido of Arezzo used the instrument in the 11th century, and in tuning instruments, including organs, into the 19th century. It states that the monochord is now used mainly for demonstration. In this older sense the instrument was a measuring and teaching device, and the sources reviewed do not connect it to any healing purpose before the twentieth century.

Multi-string instruments for lying on

Clinical papers describe the modern body monochord as a different instrument from the single-string demonstration device. A 2025 randomized trial in multiple sclerosis says its treatment monochord was designed by the music therapist Joachim Marz in Switzerland in the 1980s, with 55 strings under a resonant body that a participant lies on. A 2017 study from a Berlin hospital describes a wooden resonance box on four feet, built by a Berlin instrument maker, with strings below the box.

These accounts name different builders and designs, and the sources reviewed do not give a settled history of who first made a monochord to lie on. A 2023 oncology trial cites only a manufacturer's website for its instrument. The claim that the body monochord was developed by any one person or movement therefore remains unverified on this page.

Relation to sound massage with singing bowls

The Peter Hess Institute in Germany dates the development of Peter Hess sound massage with singing bowls to 1984 and records a professional association for the method in 1999. Its timeline does not mention a monochord or a sound table. Monochord therapy and bowl-based sound massage are therefore documented here as related but separate receptive sound practices that overlap in the German-speaking sound field.

Names in use

Papers use several terms for the same family of instruments, including body monochord, treatment monochord and, in German, Körpermonochord and Klangliege. Study authors also use monochord music or monochord sounds for recorded or live playing, and sound meditation for group sessions. The words body monochord and treatment monochord refer to the multi-string instrument for lying on, not to the single-string instrument of antiquity.

Music therapy, sound therapy and sound massage

Most trials in this field place the monochord in receptive music therapy, in which the participant listens and feels rather than performs. An Italian review of singing bowls argues that vibration-based practices belong to sound therapy rather than music therapy because they lack a therapist-patient relationship, which shows that the boundary between the terms is disputed. A 2017 study describes the monochord as body-oriented music therapy.

Sound massage in the Peter Hess sense refers to placing and playing singing bowls on or near the clothed body. It is a different method from monochord therapy, although some practitioners and teaching bodies offer both under a sound-method heading.

Instrument and setting

Published trials describe a wooden resonant body with many strings mounted underneath. In the multiple sclerosis trial the strings were tuned to two notes, while a Berlin study reports strings tuned in fifths. Participants lie supine on top of the instrument, so sound reaches them through the air and as vibration through the body. In the multiple sclerosis trial the room was held at 22 degrees Celsius and one music therapist delivered all sessions.

A therapist sits beside the instrument and strokes or plucks the strings with both hands, producing a sustained sound with overtones and without rhythm or melody, which one paper calls a sound carpet. Sessions in these trials ranged from 15 to 45 minutes and were described as receptive: the participant is not asked to make music.

Active and recorded variants

Some studies use variants. In a 2023 oncology pilot, participants lay with a smaller body monochord on the chest and played it themselves at home for at least 15 minutes in the evening for four weeks after a short introduction. A 2012 chemotherapy study used recorded monochord sounds heard through listening equipment, which removes the physical vibration that defines the lying-on format.

Uses described in the literature

Clinical authors describe monochord sessions as a way to support relaxation, mood, body perception and coping in people with cancer, palliative care needs, multiple sclerosis, psychosomatic disorders and stress. A review of music therapy in palliative care lists the monochord among newer interventions in that field, while noting that many articles did not describe the techniques used.

Mechanisms proposed by researchers

Researchers propose that sustained low-pitched sound with overtones, felt as vibration through the body, may influence autonomic activity, muscle tension and attention. The Berlin group measured skin conductance, salivary cortisol and brain activity to test this and interpreted some results as a flow-like state, though their cortisol finding ran opposite to the expected direction.

These are the aims and hypotheses stated by researchers and practitioners. They are not conclusions that monochord sessions achieve them, and the next section reports what the studies measured and how reliable the designs are.

Overview of the evidence

The searches run for this page were PubMed searches on monochord, singing bowls and Peter Hess sound massage. They found a handful of small German and Swiss clinical studies from 2008 to 2026, mostly in oncology, palliative care and psychosomatic medicine, and no systematic review specific to the monochord. No controlled trial of Peter Hess sound massage was found. A 2020 review of music therapy in palliative care mentions the monochord only as a development in the field.

Randomized and controlled studies

In a monocentric trial of 57 people with multiple sclerosis, six weekly 45-minute monochord sessions did not change the primary outcome of anxiety compared with lying on the instrument in silence (p = 0.109). Psychosocial fatigue and heat pain thresholds differed in the monochord group, but secondary results were not corrected for multiple testing, the authors report a post hoc power of 37 percent for the primary outcome, and participants could not be blinded.

A 2017 German study randomized 70 healthy adults to live monochord music or a recorded verbal relaxation exercise. Both groups showed heart-rate and heart-rate-variability changes consistent with relaxation, and differences between groups were only marginal. A Berlin crossover study of 42 patients with psychosomatic disorders found that the body monochord and relaxation music both reduced skin conductance; salivary cortisol rose slightly in both, and eight participants stopped early because of unpleasant feelings or imagery.

In a 2023 oncology pilot of 73 outpatients, the active body monochord group did slightly worse on the exploratory primary endpoint (27 percent responders) than a group listening to recorded music (39 percent), with no effects on pain or sleep. A 2012 study of 40 chemotherapy patients found comparable improvements in state anxiety after recorded monochord sounds and progressive muscle relaxation.

Uncontrolled and crossover pilots

A 2008 single-group study of 105 patients in cancer rehabilitation reported mood changes toward feeling more balanced and less nervous after monochord group sessions, with no comparison group. Two crossover trials from Mannheim in 2025 and 2026 used 15-minute sessions. They report small reductions in heart rate and pulse wave velocity after monochord interventions in 43 and 50 patients, and the 2026 authors call the findings hypothesis-generating because the design was open-label and had no no-sound control.

Related evidence on singing bowls

Systematic reviews of singing bowls, which are separate instruments, describe small and heterogeneous bodies of evidence. A 2020 review found four studies and declined to recommend bowl therapy at that stage, while a 2025 review of 19 clinical studies reported potential for reducing anxiety and depression and noted that results came from varied designs. These findings concern bowls and should not be carried over to the monochord.

Adverse events and exclusion criteria in trials

The multiple sclerosis trial reported no adverse events and excluded people with serious psychiatric disorders such as acute severe depression or suicidality, pregnancy, severe hearing impairment unless adequately aided, inability to lie supine for 15 minutes, and numbness on the backs of both hands. These are trial eligibility rules, not clinical guidance. A 2023 oncology pilot reported no monochord-specific adverse events.

In the Berlin crossover study, eight of the patients with psychosomatic disorders stopped treatment early because of unpleasant feelings or imagery, seven during body monochord exposure. The authors suggest that the relaxation state may have been experienced as an emotional challenge. Sessions can therefore evoke distressing experiences in some people with psychological vulnerability.

Contraindications and care boundaries

The sources reviewed do not provide a verified list of contraindications for monochord therapy. Practitioner websites commonly mention implants, pregnancy and epilepsy, but these were not accepted as sources here because they are practitioner pages and differ from one another. The Fachverband Klang page reviewed does not mention contraindications. Anyone with a medical condition should discuss sound therapy with a physician, and it should not delay or replace necessary care.

Training and practitioner standards

The sources reviewed describe no state-regulated training for monochord therapy. The Internationaler Fachverband Klang-Massage-Therapie, founded in May 1999, is a professional body for Peter Hess sound methods and belongs to an umbrella organization for independent health professions, whose ethics and quality guidelines it commits to. Its certified practitioner designation requires 100 hours of seminar time, 160 hours of practice and renewal every three years. This standard concerns Peter Hess sound massage, not the monochord specifically.

In the clinical studies reviewed, sessions were given by music therapists, and the multiple sclerosis paper does not describe the therapist's training. Readers should not assume that a sound practitioner holds a music therapy qualification.