Scioly.org

icky was a euphemism for toxic when toxic is not necessary.

Mr. Cool wrote:So brass is not against the rules as it is not considered pure metal?

Not sure what you are referring to. I see no prohibition in the rules on using metal.

At the last invitational I was at, they had me diagram the ear, claiming it related to music because your ear is how you can hear it, when really, it was just physiology. I feel as though knowing the anatomy of the ear doesn't help with the physics or theory of music. Should I expect to see this at other invitationals and maybe even regionals, or was just the writers of that test being unprepared and confused?

Modder wrote:At the last invitational I was at, they had me diagram the ear, claiming it related to music because your ear is how you can hear it, when really, it was just physiology. I feel as though knowing the anatomy of the ear doesn't help with the physics or theory of music. Should I expect to see this at other invitationals and maybe even regionals, or was just the writers of that test being unprepared and confused?

Yes, knowing how the ear works is important in understanding sound. Just like you can't understand how colors work without understanding how the eye works, you can't understand how sound works until you understand how the ear works. You can understand the physics of the waves, but that doesn't explain why it is sound!

Most competitions should ask you about the human ear.

fleet130 wrote:

Mr. Cool wrote:So brass is not against the rules as it is not considered pure metal?

Not sure what you are referring to. I see no prohibition in the rules on using metal.

Oh. Maybe you're right for some reason I thought the rules said any nonmetalic material but I guess not.

Hello,

I looked through the other posts but didn't see anything on the following, so I apologize if I repeated.

I made a simple recorder for my instrument-- about 40 centimeters of 1" pvc pipe, with a wood dowel system as a mouthpiece.

however, when testing frequencies at different lengths, I obtained velocities at about 300 m/s rather than 340 m/s. I believe this is attributable to "end correction"; however, I am not sure what a reasonable end correction value is: is about 5 centimeters too long. Also, does the "end correction" change with length? (If it is a proportion of total length, about how much would it be?) As I test shorter and shorter lengths of PVC, my calculated velocity of sound increases by an increasing proportion.

Also, I am curious as to the effects of different diameters of pvc: based on theoretical physics, shouldn't the frequency be the same if the length of the air column is the same?

Thanks in advance!

doctor wrote:see if you can get maple or oak
i had trouble finding a good wood since african padauk is a little hard to come by

It isn't hard to come by, it's just hard to find a consistent width that one would could buy. Which is a major deterrent, as one has to order it, and it's expensive. Maple and oak would work, I'd think oak would work a little better. I made a marimba out of spruce, and let me tell you, it was the most painful experience ever. The nodal lines weren't parallel or straight. They often diverged at weird angles due to inconsistencies in the wood and it's grain. Stringing it was a journey of several hours. My partner(who did most of the drilling while I drew nodes and did calculations) had blisters all over his hands, and bending over while stringing the marimba (as it did not fit on a table) gave him a sore back. Youngs modulus was annoying to calculate as well as each piece had a noticeably different deflection. It is for this reason that I recommend padauk, it may be expensive, but it saves a TON of problems.

As for the physics question, diameter does effect frequency. The relationship between tube length for a resonator would be...

Tube Length= SpeedofSound/(2*frequency) + Tube Diameter/2

As for a recorder, I'm not sure how one would calculate the diameter's effect.I don't know if you can use the same equation, or if the odd/even harmonics thing matters.

I have a question about the rules.

After it has the required song printed it says that the first note, a D, is below the required octave. And yet, if my knowledge of music is accurate (which I believe it is), that D is one whole step above C4, or middle C, making it a D4. Surely it is not a D3? So doesn't that mean it is in the required octave (I'm assuming when it says mandatory scale as C4 to C5 that is the same as the "required octave"?)

Mr. Cool wrote:I have a question about the rules.

After it has the required song printed it says that the first note, a D, is below the required octave. And yet, if my knowledge of music is accurate (which I believe it is), that D is one whole step above C4, or middle C, making it a D4. Surely it is not a D3? So doesn't that mean it is in the required octave (I'm assuming when it says mandatory scale as C4 to C5 that is the same as the "required octave"?)

An octave only consists of 8 notes, so if I am correct, I believe you're talking about the allowable range, which is roughly 2 octaves if I remember correctly. the D4 is part of the allowable range, but is below the REQUIRED octave, which ranges from C4-C5

personasaurus rex wrote:

Mr. Cool wrote:I have a question about the rules.

After it has the required song printed it says that the first note, a D, is below the required octave. And yet, if my knowledge of music is accurate (which I believe it is), that D is one whole step above C4, or middle C, making it a D4. Surely it is not a D3? So doesn't that mean it is in the required octave (I'm assuming when it says mandatory scale as C4 to C5 that is the same as the "required octave"?)

An octave only consists of 8 notes, so if I am correct, I believe you're talking about the allowable range, which is roughly 2 octaves if I remember correctly. the D4 is part of the allowable range, but is below the REQUIRED octave, which ranges from C4-C5

How is a D4 below a C4?

C major scale:

C D E F G A B C

D is the second note in the scale....