bending hole 5
Look, I understand that in hole 5 you got an E blow and an F draw and there is no note in between. I just don't get why you can't physically draw bend hole 5 to an E. What makes it physically impossible? I don't even inderstand why all holes don't bend the same amount. Just because hole 2 has 2 notes between the blow and draw reeds, what is alllowing the reed to bend more than most other holes? I don't get the physics behind it. How does the reed know that we don't need to bend up to the blow hole? It's really strange to me.
Or this if you have a degree in physics!
https://www.andrew.cmu.edu/user/antaki/articles/Bahnson%20JASA%201998.pdf
Hello Rishió. We don't know why the harmonica is not able to bend all the way to the adjacent reed's natural pitch... all we can do is observe and learn. We're able to bend the notes between the higher reed and lower reed, stopping slightly (about an eighth of a tone) above the adjacent reed. We also know it's the adjacent reed that is vibrating in the full bend. There have been studies done, but I am not, and am not aware of anyone who is, aware of why.
So in hole 4, you can actually bend the D to lower than a D-flat (just an 1/8 above the C)? I was under the impression that you can only bend it to D-flat and no lower. It's just mind-boggling to me that we don't know exactly how reed bending works for such a simple looking instrument. It seems like magic. I was feeling a little stupid when I couldn't explain why you can't bend below the blow note to my friend, but now I can say - nobody knows!
Interesting articles Gary. I'll read through them...
"So in hole 4, you can actually bend the D to lower than a D-flat (just an 1/8 above the C)?" Correct. It's not exactly an 1/8 of a tone... there is no specific pitch... it's essentially just very close to the adjacent reed's pitch. All of the bends can go deeper than notated. Your goal is to generally play them in tune. You can also bend blow notes 1-6 and draw notes 7-10, the tone is just very weak and you can't bend very far, so we don't generally use them (and they do not create new pitches, thus, they are not listed).
A summary of the paper is, as I understand it, as follows:
The basic reason for the restricted range of notes that can be obtained by bending is that the process involves an interaction between the blow reed and the draw reed in a given hole. One reed may dominate the sound production and this can be called the primary reed. or both reeds can be involved. If the interaction causes the lower pitched reed to be the primary reed its tone is modulated up. So, this puts a limit on how low you can bend the notes in a given hole.
I see that Winslow Yerxa and Steve Baker are mentioned in the references in the paper.
Thank you Gary. To see a visual representation of this transfer of vibration, reference Figure 7 in Acoustical and Physical Dynamics of the Diatonic Harmonica Bahnson H.T., Antaki, J.F., Beery, Q. C. (1998). J. Acoust. Soc. Am 103(4), 2134-2144) http://www.andrew.cmu.edu/user/antaki/articles/Bahnson%20JASA%201998.pdf
Makes me wonder what would happen if one hole was a full octave apart. Could that one hole cover the entire chromatic scale?! That would be pretty wild.
I have experimented with this and with standard reeds (no customizing) the limit was reeds that were a minor-6th apart... the bend traveling around a 5th in total smoothly, from one pitch to the other. A larger interval still worked (I tested a major 6th), but there was not a smooth transition from one reed to the other, you only got a slight bend out of the draw reed and then tone disappeared until the deepest bend was sounded (the blow reed producing the pitch).
Thanks for engaging with my curiousity David even though it does nothing at all to make me a better player! Really interesting though trying to understand how the harp works.
Sure! It is interesting!
Take a look at this article to see if it helps
http://www.harmonicawest.org.au/uploads/2/1/4/8/21489518/harmonica_physi...