Which Key of Diatonic Harmonica Should I Buy?

If the search query ‘what harmonica should I buy?’ is the most common harp-related entry on Google, then the corresponding ‘which key of harmonica should I buy?’ question must be a close second.

Before we examine this in detail, though, it’s worth noting an important point: if you never perform with other musicians, and never play along to recorded music, the choice of key is fairly irrelevant. You can transpose a piece of music to suit almost any key of harmonica, as long as the designation is the same (ie major to major or natural minor to natural minor. Harmonic minor to major, for instance, would be problematic). It might sound a little higher or lower than the original, but it won’t be fundamentally different (unless, of course, you subscribe to the theory that musical keys have their own distinctive and unique essence, which I don’t).

When I was a teenager, I’d often work out on the piano songs that I’d heard on the radio. As this was in the days well before the unfettered access to music we now enjoy via Spotify, YouTube, et al, this was performed largely from memory, resulting in me knowing many songs in keys that were vastly different from those of the originals (I tended to favour D♭, A♭, B♭ and their relative minors).

Of course, when I came to play some of these songs with other musicians I had to re-learn them in the correct keys, but the point is, had I continued to play alone, this wouldn’t have been necessary (pitch-related pedantry notwithstanding!) The same is true for the small percentage of harmonica players who perform entirely unaccompanied.

Enough Preamble – Which Keys Do I Really Need, Then?

If, however, you’re one of the 99% who wants to play along to music or as part of a band, choice of key is paramount. Traditional wisdom says that C, G and A are the best initial harmonicas to purchase, and this is what most of the multi-harmonica packs are comprised of. Is this advice correct, though, and, if not, what should we be buying when we start playing?

Spotify data analyst, Kevin Ning, examined the key of every track in the Spotify catalogue, which is largely comprised of Western contemporary music, and produced the following chart:

Spotify Analysis of Musical Keys

One of the big surprises here is the popularity of G major. In other analyses of popular music keys (albeit usually with much smaller datasets) C major has been shown to be the most widely used key by a significant margin. G major has usually been a distant second – often around half as frequently used as C major.

It has been posited by various commentators that C and G are both keys that are relatively easy to play on guitar and piano – historically the most popular instruments with which to compose music. Whilst I don’t disagree fundamentally with this, I would say that D major and E major, for me, are easier keys to work with on guitar (the latter key of which is a distant 11th in popularity in the Spotify catalogue), and Db, Ab, Eb and Bb are much nicer to use on keyboard (the latter especially for bluesy and jazzy pieces).

Flat keys, however, are not easy to work with on guitar, unless you’re using altered tunings, so maybe the popularity of C and G major is related to the need to find a common key that is the best compromise for the two most popular instruments.

The Useful Bit!

So, what does this tell us about the keys of harmonicas we should initially purchase? As most beginner lessons assume the use of a C harp, it’s probably safe to say that this should be our first choice, if only because it enables playing along to pre-recorded material in these lessons.

The next key should probably be A major, which, although only fourth in the chart above, is useful for a number of reasons. The majority of diatonic harp players are focused on the blues, and, as it’s easier to play this style of harmonica in the second position (cross harp), an A major harmonica translates to the key of E major. Whilst this only accounts for around 3% of music on Spotify, its popularity in the blues genre, which is only a small subset of the Spotify catalogue, is much greater. Similar justifications can be made for G major, D major and E major, in order of popularity.

Of course, this all assumes that the player is most interested in Western pop or blues-based music. Should you be a fan of playing ethnic or traditional folk music, then you would be better served by the likes of harmonic minor harps.

Returning to major key harps, once you have equipped yourself with C, A, G, D and E, it is worth considering E♭, especially if you like to play music which features horn sections, which often play in  B♭, (which, of course is an E ♭ harp in second position). The only possible disadvantage to this harp is that it is at the higher range of the pitch register, so a low E♭, so, a low E♭, if it is available in your choice of harmonica, may sometimes be preferable.

Once you have the most popular keys, it’s then up to you to decide whether you want to expand to the standard 12 major keys, or venture into new areas, such as low and low low keys, or natural and harmonic minors. The great thing about the diatonic harmonica is that the relatively reasonable pricing of even fairly high end models means that an entire set of harps in every imaginable key can be purchased for less than the price of a half decent guitar, for instance. Just remember to keep them clearly labelled!