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If you play the harmonica or are thinking of playing the harmonica, you might want to know what key harmonica to use with guitar.

There are plenty of reasons why you would use a harmonica with a guitar, but there isn’t a simple answer when deciding which key to use.

That is why we have put together this informational guide to explain what goes into deciding which key to use for your harmonica, when you need to consider an instrument that offers multiple keys, and more.

Musical Keys

There are many different keys for a harmonica just the same as there are for guitar.

In order, they include:

  • C major
  • C minor 
  • D flat major
  • C sharp minor
  • D major
  • D minor
  • E flat major
  • D sharp minor
  • E major
  • E minor
  • F major
  • F minor
  • F sharp major
  • F sharp minor
  • G major
  • G minor
  • A flat major
  • A flat minor
  • A major
  • A minor
  • B flat major
  • B flat minor
  • B major
  • B minor 

That said, when you choose a harmonica, you can choose one that is available in only one key, or one that covers all of the 12 notes in a western chromatic scale and therefore can be used to play multiple keys.

When you look at the musical key for other sheet music, if you see the musical key is E, then the harmonica key is A.

Likewise, if you see the musical key is A, then the harmonica key is D.

If the musical key is G, then the harmonica key is G. IF you see the music key is C, then the harmonica key is F.

For a music key of D, the harmonica key is G, and for a music key of F, the harmonica key is B flat. 

As you start looking for a harmonica key based on guitar keys, it’s really going to take some trial-and-error for you to figure out what guitar chords are and then convert them to the right key for your corresponding harmonica, but with a little bit of practice it will become second nature.

What if I don’t know anything about keys or reading music?

If you don’t know much about different musical keys, or how to read sheet music, then your best bet is to start with this knowledge and once you have a stronger foundation you will be able to decide which keys you will need for your harmonica based on the guitar music you are playing or what songs you were playing along to.

To learn this information you can of course take private lessons from a music teacher, and if you already have a guitar teacher or a harmonica teacher, you might go to them.

However, you can also learn through books especially books that have a lot of images dictating how to easily identify the chords and subsequently the keys of different guitar music based on the fingering.

 Other options include online lessons through music schools or virtual teachers, even the ample online resources that are available to help you understand basic chords and bending, first position, second position, and more. 

Solo or group performances

If you are investigating the right harmonica key for guitar, you may or may not be playing on your own. If you intend to play by yourself with a harmonica and a guitar, it doesn’t matter what key you use.

Realistically any song can be played in any key no matter the original key in which it was composed.

In fact, changing the composition of a song from one key to another, called transposing, it’s something that many sheet music manufacturers will allow you to do automatically if you want a specific key that is something other than what the original artist had.

However, if you are going to play with someone else, maybe you played the harmonica and they play the guitar, or you want to play along to a specific recording, the key that you choose is going to be governed by what music you are playing and in which key it is written. 

The music you are playing

The music you are playing will go a long way toward determining what key is best for you.

Given how many different keys there are around the world, the type of music you play is going to heavily influence which keys are likely to crop up and therefore which Keys you should get for your harmonica.

When you play music you can choose which key you want to use and there are different musical characteristics associated with different keys.

For example, F minor is usually a key associated with funeral music, something that’s very depressive while E major is something very happy. Love music, pop music, or Christian music might use a minor, but C major is the most common you will find especially with music written for the harmonica. 


With a harmonica, you need to know whether you will be using first position or second position. if you plan to play simple melodies or you want to play folk music then you will very likely be using first position.

First position means that you start with the blow and you accent the blow chords and the blow notes.

For this you usually get harmonica in C.

Blues music is typically written in keys like E, A, G, or C, but E, A, and G are the most common.

So, if you are planning to play more expressive music like blues, rock, pop, or country, you will be playing with second position.

Second position that means you start with the draw and you accent the draw chords and the draw notes, and you use techniques like bending.

The pattern for your notes, your chords, and your bends are going to be the same even if the note layout for every key is different.

So, if you learn to play Jingle Bells when a C major harmonica, you can use the same blow or draw patterns to play Jingle Bells on any other major key like G or A.

Now, that’s all well and good if you know what kind of music you are going to play, but if you don’t yet know, or you want more time to practice and find the type of music you want to play, then don’t fret, and start with C.

Chromatic versus diatonic harmonicas

As mentioned, you can choose a chromatic or a diatonic harmonica, and if you choose a chromatic you can play multiple keys so all you need to do is figure out what the music is in that you are trying to play or which key you can transpose it in and be on your way.

But if you are investing in a diatonic harmonica, you can only purchase one key so you might end up needing more than one harmonica.

Traditionally, most players are advised to invest in a harmonica that is in the key of C. The key of C is what most harmonica instruction books will have, and harmonica lessons, and most written sheet music are going to be written in the key of C.

So what do most harmonica players do if they find that the music they have is in a different key? They go out and purchase a new diatonic harmonica in whatever key they need for that particular music.

This is why many intermediate and advanced harmonica players will have a small carrying case inside of which are five, six, even seven different harmonicas.

The Best Key 

When you go about selecting the best harmonica for your guitar, you are likely:

  • Selecting a harmonica to play with your guitar as an individual or, 
  • Selecting a harmonica to play with another musician who is playing the guitar and you need something to work with the other musicians

When you go about choosing the right harmonica, you need to take into consideration the music you will be playing.

This can be a personal decision, if you are doing a solo performance with harmonica and guitar, or a group decision if you are playing music with a band. 

So which keys should you invest in if you were going to buy multiple harmonicas?

If you are going to get diatonic harmonicas it is good to have:

  • A
  • B flat
  • C
  • D
  • F
  • G

With these you can cover most playing situations.

What key harmonica to use with guitar

Knowing what key to use with guitar will go a long way toward helping you to figure out what key to use when you are playing certain music, what harmonica to pick up if you have a collection of diatonic harmonica, when you play with a group, and so on.

As you first start, the key of C is going to be the best option for you and of course as you continue to expand you can head over to a chromatic design or add additional keys to your collection of diatonic harmonicas.

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