# Experiment related to music?

1. Mar 22, 2009

### Epsillon

Experiment related to music??

Anyone know any good experiments related to music? I have been looking and all I can think of is an experiment which verifies a formula that is well known. It has to be something that is not well known but at the same time it cant just be a demonstration it has to have some sort of relationship

Thanks

2. Mar 23, 2009

### cragar

Re: Experiment related to music??

i remeber one of my teacher had like this pipe with holes drilled in it
and he had it hooked up to a propane tank and then he lit it and it was like a long tube burner with the individual flames coming out of it
abd then he had it hooked up to the radio and he had the speaker hooked up to it some how and when the sounds waves traveled through the propane gas you could see the wavelengths in the fire it was pretty kool , and he ahd it hooked up to something else that would emit a very specific frequency so we could see the crest's very nicely.
i hope this is what u ment

3. Mar 23, 2009

### Epsillon

Re: Experiment related to music??

Wow that would be interesting to do! However I dont think that will give a relationship which I can graph :(

4. Mar 23, 2009

Staff Emeritus
Re: Experiment related to music??

It is well known that wind instruments go out of pitch when they get cold. Why? Don't guess - measure.

5. Mar 23, 2009

### Epsillon

Re: Experiment related to music??

How do you measure pitch?

6. Mar 23, 2009

Staff Emeritus
Re: Experiment related to music??

With a tuner.

7. Mar 23, 2009

### dE_logics

Re: Experiment related to music??

Do we have equations defining beats which human brain likes?

8. Mar 23, 2009

### Danger

Re: Experiment related to music??

One of Isaac Asimov's essays dealt with a mathematical relationship between music and human appreciation thereof. Unfortunately, I can't find the book right now. (I have several of his 'collected essays' volumes.) I think that it was 'Analog' magazine for which the original columns were written, so you might be able to track it down. It was actually quite cool; almost a how-to book for songwriters.

Last edited: Mar 23, 2009
9. Mar 23, 2009

### EikeJMaas

Re: Experiment related to music??

I once did a science fair project investigating how environmental humidity would affect complete destructive interference. I didn't get the waves to fully "destruct"; beats only dimmed the volume from 3dB to 5dB, or about 1/2 to 1/3 the amplitude (went from 54dB starting to 49-51dB after cancellation). *Remember that 3dB represents a perceived doubling or halving of the loudness. Sorry if you already knew that. There was a slight correllation... I forget what it was, but it was there.

My independent variable was humidity level (adjusted from 30%, in increments of 10, to 80%).
My dependent variable was dB level.

Hope it helps... maybe you could build on this or something. I've never found any conclusion to this problem online, so it's not something that's "known" technically.

Also, sorry to advertise, I'm doing an independent study on music and physics for a post-AP physics class. If you want to deal more with the psychological aspect of it, check out my blog that my teacher is making me do... There are some interesting things (I think so anyway haha) and lots of points that might lead you to a really interesting question. And if you decide to do something related to it, tell me your results! I really want to make my project a collaborative effort, not just my own findings/opinions. https://www.physicsforums.com/showthread.php?t=301447

Last edited: Mar 23, 2009
10. Mar 23, 2009

Staff Emeritus
Re: Experiment related to music??

3db is an actual doubling of intensity. A perceived doubling takes ~10 dB.

Many of the suggestions describe the perception of sound. This is psychology, not physics. Nothing wrong with that, but it's best not to confuse one with another.

11. Mar 23, 2009

### EikeJMaas

Re: Experiment related to music??

Oops. Thanks for the correction Vanadium.

The destructive interference science fair subject that I did was pure physics. But the stuff on my blog that I'm doing as a project for school now is a very heavy mix of physics and psychology. It's amazing to see how intricately the two mesh together, though, in the context of music.

12. Mar 23, 2009

### dE_logics

Re: Experiment related to music??

We always have noise canceling ear/headphones.

Though it doesn't have to do with humidity :tongue2:

13. Mar 23, 2009

### Epsillon

Re: Experiment related to music??

How about how temperature effects pitch?? or amplitude of wave??

of a string.

And how do I measure the propeties of waves? any good softwares?

14. Mar 23, 2009

### EikeJMaas

Re: Experiment related to music??

Temperature affects a string in this way: due to specific heat capacities in a string, especially a metal one, the string will get longer as it gets warmer, or shorter as it gets colder. As it gets longer or shorter, the tension decreases or increases; the frequency of a note on a string is directly affected by the tension in a string and by the mass-per-length of the string (called linear density). So as these two variables change, so does the frequency. I forget the exact equations unfortunately, but they should be very very easy to find.

15. Mar 23, 2009

### Epsillon

Re: Experiment related to music??

Ok so I will cahnge temperature to see how it effects frequency.

How exactly would I calculate frequency?

I was looking at vernier softwares cant find anything.

And Why does the tension effects frequency due to the speed?

16. Mar 23, 2009

### EikeJMaas

Re: Experiment related to music??

You can find programs online, you just need a computer w/ a mic.

As for the equations... my book is at school right now and I can't remember the exact equation related linear density to frequency. I remember that the equation for a string/metal bar lengthening or shortening under changing temperature the equation is this:

$$\Delta$$l=$$\alpha$$l$$_{0}$$$$\Delta$$T Where the delta (the triangle) represents change over time. Alpha (the lowercase a) is a coefficient of linear expansion--this varies and is unique to each metal. "l" represents length and "l" with the subscripted 'zero' or 'naught' represents initial length. and then T represents temperature in Kelvin. This basically shows that as heat is added, the length increases and vice versa.

The equation to find linear density is mass/length. So as heat is added, length increases, and thus linear density decreases, and vice versa. Linear density is inversely proportional to frequency, but like I said, I forget that equation off of the top of my head.

If I remember I'll get that other equation to you tomorrow.

17. Mar 23, 2009

### Epsillon

Re: Experiment related to music??

Thanks everyone! Right now I got everything set except I am confused on how to strike the string with the same force. How would I keep that constant?!

18. Mar 24, 2009

### Danger

Re: Experiment related to music??

By building a mechanism to do it for you. A spring-loaded hammer or pick with a trip mechanism should reproduce the same stroke, within very tight limits, every time.

19. Mar 10, 2010

### MarNie

Re: Experiment related to music??

Hi
Perhaps not an experiment, but a phenomenon on its own is the Theremin. A musical instrument that produces a sound without touching it. Perhaps you can use some of the theory behind it for your own project (I reckon it is for school)

and some background information

http://relentlessenergy.com/theremin" [Broken]

Last edited by a moderator: May 4, 2017
20. Mar 10, 2010

### MarNie

Re: Experiment related to music??

Otherwise Cymatics is also a nice topic, (making sounds and vibrations visible)