Tuner cannot be displayed (your browser is ignoring the applet tag).

This means that the Java plugin for your browser is either not installed or not enabled. See below for more information.

How to Use the Tuner

When you first load the tuner page, your browser should tell you that the applet is signed by Seventh String Limited and that the signature has been verified by a trusted source (Thawte in fact). You will need to click the "Run" or "Ok" or "Trust" button to allow the tuner to run. See "Security Issues" below if you want to know why this is necessary.

You need to get the signal from your instrument into the computer of course. You can plug an electric instrument directly into your computer. With an acoustic instrument you will need a microphone, unless your computer has a built in microphone. If the signal is not registering on the tuner's Input Level meter then see "Sound Input Selection" below. For best results, the signal should take the meter at least half way across the scale.

Notes are named as, for instance, "F# 4 -3 cents". The first number is the octave, so C4 is middle C, C5 is an octave higher. The second number is the tuning error in cents - hundredths of a semitone (or "half step").

This chromatic tuner is sensitive (it can get an accurate reading from a quiet sound) and robust (when a note is being played, it is not easily distracted by extraneous sounds). With some tuners you have to be careful about exactly how you play the note. With this tuner, such care should not be necessary. The ability of the tuner to hear notes even against a background of ambient noise does mean that when there is ambient noise with no note being played, the tuner will tend to pick random notes out of the ambience from moment to moment. So in this situation the tuner will randomly wander around, imagining notes. I deliberately kept it this way since if it was less sensitive then it would be less able to detect notes which are being played.

If you want to tune notes which remain totally steady for a long time then you will need to uncheck the "Hum cancellation" box, to prevent such very steady notes from being ignored.

If you want a tuner which plays reference notes for you to tune to, then see the Seventh String Tuning Fork.

The Tuner Controls In Detail

The "Input" box shows the input level the tuner is hearing, and the input frequency and note. This is not affected by any change to Tuning Origin or Transposition (see below).

The "Run/Stop" button is used to turn the tuner on or off. The tuner uses a modest but significant amount of processing power. If you are using power-hungry applications such as multitrack recording software, then you may find it useful to be able to switch the tuner off. Closing the tuner window also stops it of course. However, hiding or minimising the tuner window may not stop it, depending on your browser.

The "Preferences" box has various settings.
• You can set the Tuning Origin. This is the note which will be reported as "A", normally 440 Hz. By adjusting this, you can tune to a higher or lower pitch which you can specify in either Hz or cents.
• You can set a Transposition, which effectively changes the tuning origin as well, but in whole semitones. For instance if you play tenor saxophone then you might select "Instrument in Bb" which will cause your "C" to be reported by the tuner as "C", even though it's really concert Bb.
• You can select "Use Sharps/Flats/Both". With "Both" (the default) you might see for instance F# or Bb. With "Sharps" the same two notes would be F# and A#, and with "Flats" they would be Gb and Bb.
• "Hum cancellation" is checked by default, meaning that the tuner will ignore notes which remain constant for more than about 10 seconds. In fact it will do this for any constant notes, not just 50Hz or 60Hz. Hum cancellation is normally useful but you can switch it off if hum is not a problem, or indeed if you want to use the tuner to monitor the frequency of your mains electricity supply. Many soundcards have significant hum levels.

The "Note" box reports what note the tuner is hearing. This includes the effect of any Tuning Origin or Transposition you have applied.
• The note name appears large in the middle, and also smaller at the left with the octave number and tuning error in cents.
• If the frequency is within 0.5 Hz of 50 or 60 Hz then a warning message "Mains hum?" will appear.
• Then there is the strober : blue bars which move to the left if you are flat, or to the right if you are sharp.
• Then there is the tuning meter, from -50 cents (quarter tone flat) at the left to +50 cents (quarter tone sharp) at the right.

Sound Input Selection, with some notes about different systems

Computers typically have multiple sound inputs such as internal mic, external mic, line in, etc. So you need to tell your computer which input it should be listening to, and perhaps adjust the volume too. This is usually done by selecting the "recording" device, which is typically done in your computer's Sound setup. You may need to "refresh" the tuner page after making changes. See below for more specific instructions. The tuner's Input Level meter will indicate the level of signal it is hearing, so if the level meter isn't responding then something is wrong.

Windows Vista & XP: By default have no Java plugin, but in fact most people will already have installed the Sun JRE at some point and if you haven't then you can, click here for more information and instructions.
Selection of recording device is usually found in Control Panel - Sound / Multimedia. But it may be necessary to use a separate "mixer" program provided with your sound hardware.

Mac OS-X: By default has the Sun Java plugin. You select which input to use for sound in System Preferences - Sound - Input. I find it is necessary to "refresh" the tuner page after making changes.

Linux with ALSA: I've tried Ubuntu and Red Hat. In a console, run alsamixer. You may need to press <tab> to select the "capture" view. Use left and right arrow keys to scroll sideways through the available devices. Hit <spacebar> to select a device for input. The currently selected input capture device will say "CAPTUR" in red. Up and down arrow keys adjust the volume. For more info, "man alsamixer". The tuner may work with other sound managers than ALSA, but I haven't tried it.

Windows 2000: I've had no luck with Internet Explorer (which by default has the Microsoft Java plugin, which doesn't work for us - grey box, and "class not found" message in browser status bar. The Sun JRE can be downloaded and installed, the applet then attempts to run but unfortunately it can't open the sound input line - you get a grey box with an "Audio input not available" error message). However I've been told that if you install the Firefox browser it works.

Windows 95/98/ME, Mac Classic: I haven't tried them.

Tuning Technicalities

Tuning adjustments or discrepancies are normally measured in "cents". A cent is a hundredth of a semitone. The difference between tuning to A=440 and A=441 is about 4 cents.

The range of this tuner is from 20Hz (E, an octave below the lowest note on a four string bass) to 10kHz (more than an octave above the highest note on a piano). If you are interested then here is a table giving the frequencies of musical notes.

This tuner uses the even tempered (aka equal tempered) scale, where an octave is a frequency ratio of exactly two and a semitone is a frequency ratio of exactly the twelfth root of two. In the real world however many different temperaments may be used - see en.wikipedia.org/wiki/Musical_temperament - and octaves too can vary in size, see en.wikipedia.org/wiki/Stretched_octave.
If you really want to then you can tune to other temperaments, as long as you know how much you want each note to deviate from equal temperament. For instance I find that the bottom string on my seven string guitar sounds better if I tune it about 10 cents low. So that's what I do, watching the pointer on the cent scale and ignoring the strobe.

The tuner is accurate to a tiny fraction of a cent except at the very bottom of its range. Below 40Hz the error can reach one cent and by the time we get down to 20Hz it may reach 2 or 3 cents maximum. This is unlikely to be a problem as the ear is also considerably less sensitive to the pitch of such extremely low notes.

Another possible source of error is the accuracy of your sound card clock. If it is not exactly 44100Hz then this will cause inaccuracy, and there is no way the tuner can know. A quick look around the web shows that sound card clock accuracy of 50ppm (parts per million) is considered pretty good and is in fact achieved by many sound cards. This is equivalent to an error of about one tenth of a cent, which is excellent for our purposes. But it is conceivable that a poor quality sound card might have an error big enough to notice. Sound card clock speed can also vary with temperature.

Security Issues

Allowing applets to input sound has security implications, as it might allow malicious people to write applets which would eavesdrop on conversations near your computer! The Seventh String Tuner does not, of course, use the sounds it hears for any purpose other than tuning, nor does it save any sound or send any data to any other location.

However, because of this issue, browsers will not typically allow unsigned applets on webpages to input sound. That's why the tuner applet is signed by Seventh String Limited, and you must give it permission to run when asked. If you don't give permission then the applet will report that it is unable to input sound. If you refuse permission then merely reloading the page will not give you a second chance : you must exit your browser completely (close all open browser windows). Then relaunch the browser, revisit this page, and you will be asked for permission again.

As far as I know, the default Java applet security settings for all browsers are that unsigned applets can play sound but not input sound, while signed applets can also input sound if you give permission when asked. These security settings can be changed but that's strictly for experts and I'm not going into it here.


The tuner is a Java applet so if it isn't working properly, or isn't displayed at all, then this is most likely to be a problem with running Java in your browser.

First, try simply refreshing this page. If that doesn't work then try closing all browser windows, then relaunch your browser and visit this page again.

If that doesn't fix it then click here for more information and instructions.

Downloading and Running Locally

We do allow you to download the Seventh String Tuner in order to run it locally on your computer without being connected to the internet. You may also freely distribute the downloaded zip file - see "License Terms and Conditions" below.

Click here to download it as a zip file.

Unzipping the file will get you a folder containing tuner.html (the page which displays the applet - this page in fact), sst150514135526.jar (the applet itself) and a tuner icon. Double-click tuner.html to open it in your browser and run the tuner. You can bookmark this page in your browser for quick access subsequently - it doesn't make any difference that the page is stored locally on your hard disk rather than on the internet.

If you encounter any problem then click here for more information and more detailed instructions.

License Terms and Conditions

The Seventh String Tuner is Copyright © 2007-2011 Seventh String Limited. All rights reserved. We provide it on the Seventh String website for free use by anyone, subject to the following conditions:

  • You may use it as provided on our website and you may download it for local use as described above, but you may not host either the Java applet or the html page which contains it on any other server. You are welcome to link to it from your site : you must link to http://www.seventhstring.com/tuner/tuner.html
  • You may not display the Seventh String Tuner within a containing page, for instance by using an html frame or iframe or any other framing technique. If you do link to it then you must do so in such a way that it displays in its own browser window or tab, with the usual scrollbars so the user can access the whole page.
  • You may freely distribute the downloaded zip file, as long as you distribute it exactly as downloaded, without modification.
  • You may not modify, decompile, reverse engineer, disassemble, or create derivative works of the Seventh String Tuner or any part of it.
  • While we make all reasonable efforts to ensure that the Seventh String Tuner is bug-free and performs as it should, we cannot guarantee that it will always perform as expected or accept any liability for any aspect of its use.
  • We do not promise to provide support but in fact you will probably get a helpful reply if you email andy@seventhstring.com. Please read the "Problems?" section above, first.
  • This License will be governed by the laws of the United Kingdom. If for any reason any part of this agreement is unenforceable, the remainder shall continue in full force and effect.

Related Software From Seventh String

Seventh String Software also provide Transcribe!, the world's leading software for helping musicians to figure out music from recordings.

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Build date : Thu May 14 13:55:26 BST 2015