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David's Tip of the Day: Mechanical Resonance - How the Tuning of your Mouth Effects a Reed

David Barrett Admin's picture

Stuff You Should Know releases on Tuesdays and Thursdays and is one of my favorite podcasts to listen to. On Tuesday the subject was "Bridges: Nature Abhors Them" and at 48:21 they speak of mechanical resonance in regards to the Tacoma Narrows Bridge disaster. Believe it or not, the understanding of this will help you to become a better harmonica player.

Everything in our universe has a resonant frequency. Simply put, every object has a frequency that it gets excited at. If you play a note at an object's resonant frequency the object will vibrate. This frequency can come from a sound wave (traveling through the air) or from a vibration in a physical medium (a car rumbling by). Co-host Chuck Bryant wasn't surprised to hear about this from their research... he's a guitar player, and as musicians we're around this more than you may think.

You may have noticed that when listening to music loudly that an object in the room will vibrate when the bass hits a particular note (lower frequencies have more energy that higher). You may notice the same thing when your amp has a particular buzz when playing a specific note (commonly a loose speaker nut, but sometimes it's more serious, it's in the actual tuning of the cabinet... yes, manufacturers tune their cabinets). My upright bass has an annoying buzz when I hit my open A string, so it needs to take a trip to the local luthier to fix the internal bracing that's most likely come loose.

Josh Clark states "Building designers, bridge designers, they will fine-tune a structure so that it will resonate at a frequency that it's probably never going to encounter." This is the same principle of tuning your mouth when playing the harmonica. Roughly 70% of new harmonica players have difficultly playing the 2 draw (to the point that many new harmonica players return their new harmonica, thinking that it's a defective instrument). The problem?... their mouth is tuned to a frequency that's messing with that reed's ability to vibrate. It's the issue of the podcast in reverse. In most cases the player's mouth is tuned to a frequency just below the reed's vibrating frequency, causing it to slightly bend in pitch, be airy in tone, squeal or not sound at all.

How do you fix this? You do the same thing that the designers Josh mentioned do... tune your mouth to a pitch that the reed will not be effected.

You can achieve this in three ways...

1) Tune your mouth to a higher frequency. BUT, if you tune your mouth higher in pitch than that reed, then your tone will suffer. Your mouth is the resonant cavity for sound production on the harmonica, so if you tune it smaller, you'll get a smaller, more wimpy tone. Not good!

2) Tune your mouth to a lower frequency. Good! If you tune your mouth to a pitch that's lower than that reed, and its ability to bend (if you tune your mouth just below the reed's pitch, then you'll create a bend), then you'll not only be out of the offending frequency range that causes the 2 draw issues, you'll also have big tone. How is this done?... by lowering the middle and back of your tongue. If you use this large embouchure for all of your playing, not only will you not have issues with the 2 draw when it's hit in a run, the size of the mouth cavity needed to play the 2 draw without issue is a nice embouchure size for overall playing over the entire range of the harmonica.

3) Tune your mouth exactly to the pitch of that reed. This is used by advanced players. If you have some years of bending under your belt, your mouth has learned how to tune itself to every reed that you play. This is what allows an advanced player to bend at the slightest movement of the tongue. If you're having issues with the 2 draw, then you're not this player, but I just wanted to make you aware of what awaits you in the advanced stages of playing.

No tips of the day next week due to a busy filming schedule, this is why I wrote a long one for you today.
Have a great weekend everybody. Here's the link to the podcast:

Stuff You Should Know - Bridges: Nature Abhors Them