Overblow Technique on the Diatonic Harmonica
The diatonic harmonica, as its name indicates, is designed for playing the notes of a diatonic scale. On standard Richter tuned diatonics these are the notes of the major scale. The full scale can be played on the second octave, but in the first and third octave some notes of the scale are missing.

When we look at the C harmonica and the C major scale, the missing notes in the first octave are the F and the A, in the third octave the B is missing.
These notes can be played by bending.

The blow- and drawbends add a large number of notes to those that can be found on a Richter tuned diatonic, however not all 12 notes that are used in western music can be played on the Richter diatonic by using bent notes.

The notes that are missing are, when we look at a C harmonica:
- The Eb in the first octave.
- The Eb, F# and Bb in the second octave.
- The C# and Ab in the third octave.

These notes can be played by using overblows and overdraws, giving a complete chromatic scale over three octaves.

Chromatic scale - C Diatonic

User Contributed Notes
26-06-2021 18:40
Thank you Gary
26-06-2021 18:36
Gary Sellars
Tinus i'm sorry to hear this. I got dystonia in my picking hand and it wrecked my guitar playing. It causes the pick to twist and slip and it's hard to control. I still play but it's much harder to do. I'm very sorry for your illness. Best wishes.
26-06-2021 18:27
I don't, I suffer from hyperacusis so playing harmonica is no longer possible
26-06-2021 18:25
Gary Sellars
You mean you don't play anymore?!! Surely not?
26-06-2021 17:53
When I still played I did yes. Everything on a C harp. I tried other harps like Bb and Eb but I didn't like it.
26-06-2021 17:51
Gary Sellars
Do you play everything on a C harp Tinus?
31-07-2017 23:55
Lawrence Romeo
Great site. Thanks for promoting Harmonica in such a positive way. I'm a folksy player since 1987!
Keep doing what you do best!
05-04-2013 05:23
hi, i am dewo gundhul from bandung indonesia. i found my old harmonica that bought 30 yrs ago, tombo chromatic, tremolo and 3 pcs of diatonic. i am interseted to play it, thanks for telling me some advise eventhough undirecly by reading your conversation in this faq harmonica. hopefully helping me ..........
22-12-2012 02:48
@Carter: practice bending with a tongue block that usually really improves tone and control. Make sure that the gapping of the reeds is good. The blow reed should be gapped really tightly and the draw reed so that it can at least produce the half step bend but chokes just before the whole step bend.
21-12-2012 21:27
Thanks to your helpful instructions, I've been able to achieve some overblows. However, it seems to me the greater limitation to full chromatic playing is the poor sound quality of sustained bent notes, especially the draws on the three hole, such as the A on a C harp. I listened to your sound clips and you have good tone on the three draw. How can I get better tone on the draw notes?

Thanks for a great website.

15-07-2012 18:38
Let us take hole 8 ( E blow/ D draw)
By theory :
• Blowbend on it means E to be Eb
• Overbend on it means D to be D# which is equal to Eb
Using a guitar tuner while blowing on hole 8 how do I know if I succeeded blowbend or overbend??
15-07-2012 18:37
Let us take hole 8 ( E blow/ D draw)
By theory :
• Blowbend on it means E to be Eb
• Overbend on it means D to be D# which is equal to Eb
Using a guitar tuner while blowing on hole 8 I take D# how do I know if I succeeded blowbend or overbend on it??
19-12-2011 23:03
@John: yes if you say it is up a half step from what it should be then you should bend it down, you apparently are already able to bend it up. However you can experiment with it, up and down. Overblows can bend up very far.
19-12-2011 23:00
John kane
ok but do i have to bend it down?
19-12-2011 21:45
@John: yes take the covers off and block the blowreed, that way you can play just the overblow without having to worry about the blowreed.Then just bend the overblow up and down so you get a feel for where the right pitch is. Then learn to start the note on the correct pitch and only then try it with the blowreed unblocked.
19-12-2011 21:11
John kane
hi tinus, first of all thanks for all the usefull information.
iam just begininng to overblow, i can choke the reed with ease, can get a sound from the other though its a bit weak, and also its 1/2 step higher than it should be, do you have any suggestions??
11-12-2010 23:23
11-12-2010 22:41
Thank you for your reply, but what did you mean
"need a little more adjusting and maybe a little wax"

Do you use wax somehow? What kind of adjusting? Mouth or actual tinkering inside the tin sandwich?
07-12-2010 20:40
@Robert: you can use the cheaper harps to practice on, they just need a little more adjusting and maybe a little wax. It takes about a year to learn to play a C harp chromatically, provided you practice regularly and don't spend all your time playing in second position.
07-12-2010 06:51
First of all, an immense thank you for this website!

Though I've been playing harp for about a year now I am still a newbie. My current objective is to learn to bend, regular and over, to the point that the tones come on demand naturally. I would L O V E to play a C chromatically!

I currently have a Hohner Big River, and I'm buying a sp20 this week because I hear that it is easier.

Being one not to waste money I am cautious about learning to overbend on my Hohners. I don't want to break them. So the question that I have is can I use a cheap harmonica, say the $10 hohner or something else cheap, to practice on? Or are these cheap harmonicas incapable of overbending? Honestly, I would feel better breaking a few of these than a more expensive harp.

On another topic, I got the JP Allen DVD course, and I've been randomly cruising through youtube. Are there any great (free?) websites that offer superb tutorials?

Realistically... how long (years?) could it take to learn to play a C chromatically?

Again, thanks for this awesome website! I look forward to seeing your answers :)
19-01-2010 12:32
@Ken: is that the high pitched squeel or the low one where the blowreed joins in with the overblown note? For the former you have to take a look at the page "waxing the rivet end" for the latter you need to work on your ability to choke the blowreed. Concentrate on choking the blowreed instead of on trying to play the overblow: bend down the blow note until it chokes and keep it there, without getting the overblown note. when you get the choke increase pressure slowly without losing the choke and without having the overblown note sound. That willgive you more control over the blowreed.
19-01-2010 02:37
ken k
What must I do? I have great control, musicality, and experience but everytime I try to overblow I get that squeally sound like the note is sickly and strained. I have tried closing the gap of the reed to no avail. what am I missing?
Thank you,
Richmond VA
03-07-2009 11:30
You are not wasting your time overblowing the sp20. I reccomend that harp to my students and many of them overblow the sp20 succesfully.
You will probably damage the harp, but that goes for any harp you learn to overblow on.
03-07-2009 11:19
I really appreciate people who have the generosity to share their info, so thanks.
Can anyone tell me if I am wasting my time attempting overblows on a 'Special 20'?
...and am I possibly going to damage the harp?
14-05-2009 01:32
In the example I use the overblows in holes 1,4,5,6 and the overdraws in holes 7 and 9. The other overblows aren't difficult but the notes they produce are already available on the harmonica as normal blow or draw notes.
13-05-2009 23:06
Hello Tinus:
If overblows can be accomplished in holes 1-6, why does your example only play the 4,5 and 6 overblow? Are the notes on holes 1-3 too difficult? or just too obscure and are not used very often?

Thank You
31-01-2009 12:46
Hey John,

Overblows can only be played on holes 1 to 6 on a regular diatonic. In holes 8,9 and 10 you can blowbend. Bent notes go down in pitch overblows go up in pitch. On holes 7 to 10 you can overdraw and you do not need a magic harp for it. Check out the scalefinder to see which notes are where: http://www.overblow.com/index.php?menuid=26
31-01-2009 11:09
The harmonica of choice for me to do overblows is the Honer Golden Melody. You will find it to be a plastic comb harp and more air tight. you may practice overblows on holes 4,5,6,8,9, and 10. On some special harmonicas you can get an special overdraw on the 7 hole.

Practice practice practice. I have a small pile of broken harps from over blowing on them one that even cracked the #4 draw reed. As when you overblow the draw reed vibrates to make the desired tone.
01-10-2008 13:32
"can any one sujest a good harmonica tab site"

02-09-2008 02:22
can any one sujest a good harmonica tab site
14-03-2008 17:53
After 3 weeks of trying I managed a 1 overblow and after 7 weeks have just managed a dirtly squeeky 6 over blow along with the shadow of a 4 overblow. 5 is really tricky. Overdraws seem just as hard if not more but leaving those till after a get a hang of the ob's. Thanks for you help!
30-08-2007 00:18
There is a lot of info on the web for the beginning harpplayer. The best place to start is this:
29-08-2007 23:50
greg bax
l live in australia and l love the blues. lve been playing the harmonica for 4 mths any info, tabs that l can learn would be great.
thanks happy playing
06-11-2005 17:23
Just to say that after much head scratching and squeaky hooting on my harmonica I just this second managed my first overblow on 6 blow whilst browsing your site!! Well I just had to let you know and say thank you!! Haha, I now have one more note with which to annoy the neighbours...
22-07-2005 20:13
I'm afraid this isn't Joe's site but mine. There is an interview with Joe read it here: http://overblow.com/?menuid=169
09-03-2005 02:19
richard dawson
we should do a video on harp repairs and modification. I am a cameraman working for cbc television for 25 years at the toronto station in canada. Lot of experience in video and film production. Also play harp in chicago blues style for over 35 years. Let me know what you think of the idea.
rockin rich
10-08-2004 18:44
Clive Foreman
I have just listened to your chromatic scale played on the C diatonic blues harp. ohhh wow .. thats total control
I was just about to give up learning the theory of playing my harmonica and carry on just "doing it".
This music, scales, and postion thingy is doing my head in .... but i want to learn it. After hearing that scale I realise what a long road it is from where I am now... still must keep plodding on. Thank you for the insperartion.
06-05-2004 12:41
Check out the scalefinder for a complete overview of all the overblows available.