Attention
Tone Fit Task
Also called: probe-tone ratings, probe-tone paradigm, probe-tone method, tonal hierarchy ratings, key profile ratings
Measure how well single tones seem to fit a musical key: listeners hear a chord or a short cadence through headphones, then one tone, and rate how well it fits. Ratings are compared with the major and minor key profiles.
6-8 minUntimed
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 40
- Evidence grade
- D
- Registered clinical studies
- 0
What it measures
Measures how well single tones seem to fit a musical key. Participants hear a chord or a short chord sequence through headphones, then one tone, and rate how well the tone fits. Scores compare each person's ratings of the 12 tones with the standard major and minor key profiles. There is no correct rating.
Constructs
- Tonal hierarchy
- Implicit knowledge of musical keys
- Music perception
Research uses
- Music perception research
- Musical experience research
- Music cognition research
How the paradigm works
Probe-tone ratings show how listeners hear the tones of a musical key. A chord or a short cadence sets the key, then one tone sounds, and listeners rate how well it fits. In Krumhansl and Kessler's listeners the tonic rated highest, then the other tones of the tonic chord, then the rest of the scale, with tones outside the scale lowest.
More about the paradigm
Set a comfortable volume and take the 6-trial headphone check. A failed check stops the task by default; researchers can continue with a quality flag.
Four contexts: the tonic chord and the IV-V-I cadence in a major key, and the tonic chord and the iv-V-i cadence in a harmonic minor key.
Chords of 500 ms, 250 ms apart in a cadence, then a 1,000 ms pause and one of the 12 chromatic tones for 500 ms. Every chord and tone is a Shepard tone: octave-spaced sine components under a fixed envelope centered near 370 Hz, so it has a clear note but no clear height. All sounds have equal RMS and 10 ms ramps and play 10 dB below the volume-setting tone.
Press Play, listen once, then rate from 1 (fits poorly) to 7 (fits well), with no time limit. There is no correct rating.
Each context is a block of the 12 tones in a seeded order, each block in its own key: 48 scored ratings. With 2 repetitions, all four blocks play again in new keys: 96 ratings.
2 practice ratings after the major cadence, followed by the chosen number for 1,000 ms. The task gives no advice on which tones fit.
The primary score is the mean of two Pearson correlations: major-key ratings of the 12 tones with Krumhansl and Kessler's major key profile, and minor-key ratings with their minor key profile. Each correlation, both rating profiles, the mean rating and scale tones minus other tones accompany it. Answers under 100 ms from the rating buttons opening leave scores.
Scores
- Key profile fitscore
- Mean of the major and minor profile correlations; both must be defined.
- Higher means ratings follow the published key profiles more closely; descriptive
- Major profile fitscore
- Pearson correlation between mean ratings of the rated tones after major contexts and Krumhansl and Kessler's major key profile. Null with fewer than three rated tones or no variation.
- Higher means ratings follow the major key profile more closely; descriptive
- Minor profile fitscore
- Pearson correlation between mean ratings of the rated tones after minor contexts and Krumhansl and Kessler's minor key profile. Null with fewer than three rated tones or no variation.
- Higher means ratings follow the minor key profile more closely; descriptive
- Scale tone differencescore
- Mean rating of scale tones minus other tones over both rating profiles, with the harmonic minor scale in minor; scale points.
- Descriptive; no better direction
- Major rating profilescore
- Mean rating of each tone after major contexts, keyed by semitones above the tonic (0 to 11).
- Descriptive; no better direction
- Minor rating profilescore
- Mean rating of each tone after minor contexts, keyed by semitones above the tonic (0 to 11).
- Descriptive; no better direction
- Mean ratingscore
- Average usable rating on the 1 to 7 scale.
- Descriptive; no better direction
- Median answer timems
- Median time after rating buttons open.
- Informational
- Anticipationscount
- Ratings under 100 ms, excluded from scores.
- Informational
- Completed trialstrials
- Valid ratings in the selected run.
- Informational
- Planned trialstrials
- Number planned in the selected run.
- Informational
- Headphone check passedscore
- 1 for a passed equipment check, 0 for a failed check.
- Informational
- Headphone check correctcount
- Correct equipment-check responses out of six.
- Informational
- Reported output delayms
- Output delay reported by the browser, empty when unavailable.
- Informational
Use and evidence
40 papers from 2021 to 2025 name this task in their title or abstract, up 3% compared with 2016 to 2020. That ranks it 394 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 10 |
| 2024 | 4 |
| 2023 | 6 |
| 2022 | 9 |
| 2021 | 11 |
| 2020 | 11 |
| 2019 | 6 |
| 2018 | 9 |
| 2017 | 3 |
| 2016 | 10 |
| 2015 | 11 |
| 2014 | 6 |
| 2013 | 7 |
| 2012 | 6 |
| 2011 | 5 |
| 2010 | 6 |
| 2009 | 5 |
| 2008 | 1 |
| 2007 | 3 |
| 2006 | 1 |
| 2005 | 3 |
| 2004 | 3 |
| 2003 | 5 |
| 2002 | 2 |
| 2001 | 9 |
| 2000 | 3 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 5
- Registered clinical studies using it as an outcome
- 0
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.39.0, counted 8 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Sound setup
- Set a comfortable volume and take the 6-trial headphone check. A failed check stops the task by default; researchers can continue with a quality flag.
- Contexts
- The tonic chord and the IV-V-I cadence in a major key, and the tonic chord and the iv-V-i cadence in a harmonic minor key.
- Sound
- Chords of 500 ms, 250 ms apart in a cadence, then a 1,000 ms pause and one of the 12 chromatic tones for 500 ms. Shepard tones: octave-spaced sine components under a fixed envelope centered near 370 Hz. Equal RMS, 10 ms ramps, 10 dB below the volume-setting tone.
- Trial
- Press Play, listen once, then rate from 1 (fits poorly) to 7 (fits well), with no time limit. There is no correct rating.
- Trials
- Each context is a block of the 12 tones in a seeded order, each block in its own key: 48 scored ratings. With 2 repetitions, all four blocks play again in new keys: 96 ratings.
- Practice
- 2 practice ratings after the major cadence, followed by the chosen number for 1,000 ms. The task gives no advice on which tones fit.
- Scores
- The primary score is the mean of the Pearson correlations between each person's major and minor rating profiles and Krumhansl and Kessler's key profiles. Each correlation, both profiles, the mean rating and scale tones minus other tones accompany it. Answers under 100 ms from the rating buttons opening leave scores.
Our synthetic chords and tones follow the probe-tone method, and the published profiles come from 10 musically trained listeners. Musically trained listeners followed the tonal hierarchy most closely in Krumhansl and Shepard (1979), so the fit describes ratings within this task, with no percentile. Headphones, normal hearing and a comfortable volume are required; levels are relative rather than calibrated. Results do not assess hearing or musical ability.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: tone_fit_test from the selected run, ratings from 1 to 7 after the tones finish. Ratings have no correct answer. One rating throughout and an incomplete run are flagged for review; ratings under 100 ms leave scores and invalidate when at least half. A failed headphone check is flagged when continued, and a stopped check leaves no results.
Why these rules
There is no correct option to compare with chance, so accuracy is not judged against chance. A listener can hear any tone as fitting or rate every tone alike, so repeated ratings flag review only. Answer buttons open after the last tone finishes.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| When the headphone check fails | Stop the test | Stop the test, Continue the test |
| Repetitions | 1 | 1 to 2 |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Untimed test: runs on desktops, laptops, tablets and phones. Needs headphones. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Tone Fit Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Krumhansl and Shepard, 1979; Krumhansl and Kessler, 1982), with the standard settings (when the headphone check fails: Stop the test; repetitions: 1). The main score was key profile fit (mean of the major and minor profile correlations; both must be defined).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Krumhansl, C. L., & Shepard, R. N. (1979). Quantification of the hierarchy of tonal functions within a diatonic context. Journal of Experimental Psychology: Human Perception and Performance, 5(4), 579-594. https://doi.org/10.1037/0096-1523.5.4.579The probe-tone method: listeners rate how well each chromatic tone completes a key context.
- Krumhansl, C. L., & Kessler, E. J. (1982). Tracing the dynamic changes in perceived tonal organization in a spatial representation of musical keys. Psychological Review, 89(4), 334-368. https://doi.org/10.1037/0033-295X.89.4.334Chord and cadence contexts, octave-spaced tones, timing, the 1 to 7 fit scale and the major and minor key profiles the scores compare with.
- Shepard, R. N. (1964). Circularity in judgments of relative pitch. The Journal of the Acoustical Society of America, 36(12), 2346-2353. https://doi.org/10.1121/1.1919362Tones made of octave-spaced components under a fixed envelope.
- Serra-Peralta, M., Serrà, J., & Corral, Á. (2021). Heaps' law and vocabulary richness in the history of classical music harmony. EPJ Data Science, 10, 40. https://doi.org/10.1140/epjds/s13688-021-00293-8Prints the numeric values of both key profiles.
- Woods, K. J. P., Siegel, M. H., Traer, J., & McDermott, J. H. (2017). Headphone screening to facilitate web-based auditory experiments. Attention, Perception, & Psychophysics, 79(7), 2064-2072. https://doi.org/10.3758/s13414-017-1361-2The shared headphone check.
Source papers
- Krumhansl, C. L., & Kessler, E. J. (1982). Tracing the dynamic changes in perceived tonal organization in a spatial representation of musical keys. Psychological Review, 89(4), 334-368.Paradigm source, Adults
Questions
How long does the Tone Fit Task take?
About 6 to 8 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. Needs headphones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Key profile fit, Major profile fit, Minor profile fit, Scale tone difference, Major rating profile, Minor rating profile, Mean rating, Median answer time, Anticipations, Completed trials, Planned trials, Headphone check passed, Headphone check correct and Reported output delay. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Tone Fit Task used in research?
40 papers from 2021 to 2025 name it in their title or abstract, up 3% compared with 2016 to 2020. That ranks it 394 of 582 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.39.0, counted 8 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Tone Fit Task have?
In the published research, 0 papers report its test-retest reliability and 0 registered clinical studies use it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
When the headphone check fails (Stop the test, Continue the test) and repetitions (1 to 2). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
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