Original RTTA Tool
This tool was inspired by Terry McGee's original Tartini-R Polygraph RTTA tool at:
How to use this tool
1) Select the A4 reference frequency and input level adjustment.
2) Select the temperament: Equal Temperament, Just Intonation, Pythagorean, or a Fiddle Sweetened preset.
3) If you select Just Intonation or Pythagorean, also select the root note for the temperament.
Root note is not used for Equal Temperament or the Fiddle Sweetened presets.
4) Click START and allow microphone access when prompted.
5) Play sustained single notes (a second or so each). The tool measures each note and builds a distribution of cents offset relative to the selected temperament.
6) You can change the cents range of the graph using the Cents range (display) menu.
7) Click PAUSE to pause the pitch detection. Click RESUME to resume.
8) Click the JPEG button at the bottom right of the graph area to save a JPEG image file of the graph.
The JPEG image file will be saved to your browser's default Downloads directory.
On mobile devices, rotate your device to Landscape orientation before doing the export to get the best JPEG image results.
9) Click the CSV button at the bottom right of the graph area to save the graph values as a CSV file with the median cents offset value for each note.
The exported files will be saved to your browser's default Downloads directory.
10) Click RESET to clear the graph and start over.
How to interpret the graph
Each note gets a yellow box plot:
• The yellow box is the middle 50% of measurements (25th–75th percentile).
• The black line inside the box is the median (typical value).
• The dashed whiskers show the typical low/high range (1.5×IQR rule).
Values above 0 are sharp, below 0 are flat. Taller boxes/long whiskers mean less consistency.
Pythagorean (Perfect fifths)
This mode uses pure 3:2 fifths (Pythagorean tuning).
It is ideal for tuning a fiddle so the open strings and
fifth-based double stops sound clean and consonant, with
minimal beating.
Recommended GDAE fiddle tuning workflow:
Root = D (recommended), start on the D string
1) Set the Temperament to Pythagorean (Perfect fifths).
2) Set the Root note to D.
3) Tune the D string until the tuner reads 0.0 cents.
4) Tune the A string until it reads 0.0 cents.
5) Tune the G string until it reads 0.0 cents.
6) Finally, tune the E string until it reads 0.0 cents.
Alternative GDAE fiddle tuning workflow:
Root = A, start on the A string
1) Set the Temperament to Pythagorean (Perfect fifths).
2) Set the Root note to A.
3) Tune the A string until the tuner reads 0.0 cents.
4) Tune the D string until it reads 0.0 cents.
5) Tune the E string until it reads 0.0 cents.
6) Finally, tune the G string until it reads 0.0 cents.
In both cases, the strings are tuned in pure fifths, which is why
all strings read 0.0 cents when correctly tuned.
Fiddle Sweetened (open strings pure fifths, everything else ET)
These two modes are designed for traditional fiddle tuning where you want the open strings (G–D–A–E) to be tuned
in pure 3:2 fifths for clean resonance and double stops, but want all other notes to match
Equal Temperament for compatibility with other instruments.
Fiddle Sweetened (Anchor on D)
• D4 is locked to the Equal Temperament D (based on the selected A4 reference).
• G3, A4, and E5 are derived from D using pure 3:2 fifth ratios.
• All other notes are Equal Temperament.
Recommended workflow (Anchor on D):
1) Select Fiddle Sweetened (Anchor on D).
2) Tune D first until the tuner reads 0.0 cents.
3) Tune A, then G, then E until each reads 0.0 cents.
Fiddle Sweetened (Anchor on A)
• A4 is locked to the Equal Temperament A (based on the selected A4 reference).
• G3, D4, and E5 are derived from A using pure 3:2 fifth ratios.
• All other notes are Equal Temperament.
Recommended workflow (Anchor on A):
1) Select Fiddle Sweetened (Anchor on A).
2) Tune A first until the tuner reads 0.0 cents.
3) Tune D, then E, then G until each reads 0.0 cents.
Note: In these sweetened fifths modes, the Root note selector is disabled because the anchor is fixed by the selected mode.
A4 Reference Frequency
The options include modern A4 reference frequencies from A:438 to A:446 as well as A:415 for Baroque, A:392 for French Baroque, and common Scottish bagpipes A4 references from A:465 to A:482.
The reference value is saved and restored the next time you run the tuner.
Troubleshooting
If you are having issues with the tool not hearing your instrument, please click the link below to open an audio input test utility that will check if the audio input on your system has the correct levels and settings:
You must grant the browser microphone permission for this tool to work.
The audio input level is displayed in a bar at the top-right of the tool.
If no audio is detected or the audio input meter is maxed-out and no notes are getting recognized:
This tool is designed to be used in a quiet environment.
It may not work well or at all with loud background noise or other instruments playing in the background.
To optimize the signal level coming into the tool, verify and adjust your system's microphone level settings as required to get a strong audio signal coming in.
If necessary, you can also reduce or boost the microphone signal level using the
Input level adjustment dropdown.
On Windows systems, you may also need to disable any automatic microphone noise reduction performed by the system audio drivers.
Noise reduction audio driver software may mistake continuous tones for background noise and filter them out.
Open Windows Settings, search for Microphone settings, make any required changes, and then reload this tab in your browser.
Tip Jars
This tool was created by
Michael Eskin.
If you find it useful, please consider making a contribution via my online tip jars:
Source Code
The full source code for this tool is available on my GitHub repository.
The source is completely contained in the one file:
rtta.html: