Forget about temperament! Freestyle tuning with the Tuning Card
A harmonica won't sound wrong if you tune it a little differently than how it came from the factory. Harmonicas are said to conform to a certain temperament but most off-the-shelf harmonicas are not tuned precisely enough for the temperament to matter all that much anyway.
These days, if any chords are in harmony, it's usually limited to the bottom end of the instrument.
Before the 1960s, harmonicas were in much better tune because it seems that making a perfectly-tuned instrument was the primary focus at the factory. (Little did they know the same things they were doing to the instrument to help make the chords play well also helped make it easy to bend notes!) By making today's harmonicas play with harder breath and try to last longer, we've moved away from factory-made instruments that are in perfect tune.
What is temperament?
Equal Temperament is a configuration where the pitches of all notes are divided up equally. In this configuration, chords don't sound in harmony. Tuning your harp to this configuration doesn't really require a lot of precision.
7-limit Just Intonation is a configuration where notes are slightly off-pitch to make the major chord of the scale play in perfect harmony. This configuration requires the most precision because each reed needs to resonate at an exact frequency to produce the strongest harmony.
Compromise tuning is anything in the middle, including "19-limit Just Intonation". Chords can be in tune and the notes can still sound fine when played alone. There are a few different "recipes" for Compromise tuning however there is not one best way to compromise between the two extremes.
Are octaves in tune? Compromise-tuned harmonicas are supposed to provide smooth octaves, but they often fall short. Most Equal Temperament harmonicas don't even try. What if you play octaves but don't play major chords? (Example: Playing in the style of William Clarke requires lots of octaves but hardly any chords.) You'd be very happy with Equal Temperament along with in-tune octaves which is less work than tuning for chords and octaves.
The tuning of some Equal Temperament configured harmonicas is so imprecise that some of the notes are farther out of tune than if configured for strong sounding chords.
The conclusion is: Your playing style may not align with one particular temperament. There's no need to conform to any particular configuration. You can tune a harmonica any way you like. Spend time working on the elements you need and save time by not worrying about the rest.
What should I use instead of temperament?
Decide which chords, octaves / intervals and single notes you need to be in tune.
- Do you need chords to be in tune? Which ones? Who says you can't tune half the harp for chords and the other half for single notes?
- Do you need octaves to be in tune? Do you prefer them wet*?
- Do you need the intervals of the Fifths and Thirds to be in harmony? Don't worry about any intervals other than octave, thirds and fifths.
- Lastly, does tuning for major chord harmony make the thirds sound too flat when played as single notes to your ear? If so, choose between the chord or the single note.
(*) Wetness is when an octave beats intentionally. Example: Tremolo harmonicas have two identical reeds playing the same pitch but slightly off-tune from the factory. On a 10-hole diatonic harmonica, tuning the reeds to be in perfect tune is ideal. You can hit the octave dry and if you want some wetness, you can phase out the pitch with your embouchure. You probably can't take a wet octave back in tune using your embouchure though.
I've created The Tuning Card to help you tune a harmonica freestyle - without necessarily using temperament. The Tuning Card helps you tune what you need.
Lay the plate (or the assembled harmonica) on the Tuning card. Use the colors to help you map out which reed you need to adjust.
Anyone who knows me will tell you that I do not advocate tuning "by the numbers." You won't end up with chords or octaves in tune if you simply play each note into a tuner and adjust the pitch. The pitch of a single reed played on a harmonica is not stable - it's influenced by our embouchure, our breath force and a few other factors.
Pick the method that meets your requirements:
Simple: If you never play chords or octaves, accuracy is not required. Use Equal Temperament. It's the easiest configuration. Simply use a tuner to tune all the notes to an offset of zero on your tuner. This is how most budget/inexpensive harmonicas are tuned. You can expect the accuracy of each note to be about + or - 6 cents.
Intermediate: If you like chords and octaves but are not skilled at tuning, tune only the elements you need. Tune the chords on the low end of the harmonica. Tune the rest for either smooth octaves or Equal Temperament. Chords and octaves can sound fine when tuned with an accuracy of + or - 2 cents.
Advanced: Perfect harmony gives your chords more power. Build a chord using dynamic breath for extra precision. Double check each note with the fifths and thirds. Use the octaves to tune the other chords and use their thirds and fifths to "square" - double or even triple check each reed for maximum precision. This process takes more time, skill and attention to detail. It requires accuracy and notes should be accurate to within a fraction of a cent.
Most people - even those with perfect pitch - can't pick up on 13 cents difference in absolute pitch. But relative pitch - when two notes are played together - is much more obvious to everybody, even those not gifted with perfect pitch.
The Tuning Card helps you through the process of tuning using relative values instead of absolute ones.
You can use the French Tuner™ along with the Tuning Card.
The underling principle is to play the notes you are working on together and use your ears to help you decide whether to raise or lower the pitch.