Sounds of Music C

User avatar
gz839918
Member
Member
Posts: 71
Joined: April 27th, 2019, 6:40 pm
Division: Grad
State: NC

Re: Sounds of Music C

Postby gz839918 » October 15th, 2019, 12:07 pm

What about a marimba? We did a marimba last year but we used oak since it was cheap. We are thinking of doing a maple marimba this year for better resonance. We did have some trouble with registering pitches, so a percussion based instrument may not be a great move, but it is relatively easy to build and tune. I have 3 other build events and a couple test events to work on this year, so I don't want to spend a ridiculous amount of time building and tuning an instrument while I need to work on other events. Anyone else thinking about a marimba or have ideas for fixing problems with pitches getting registered?
By a marimba, do you mean that you will include pipes as specialized resonators? If so, it may be difficult to set up such an instrument, because the range of pitches in the rules this season is very wide, meaning you'll need many pipes, and they'll probably have to be very long to reach F3. (All instruments must fit in a 100 cm by 60 cm by 60 cm box when you arrive to the event, but they can be bigger when set up.) If you make a xylophone or glockenspiel (i.e. no pipes), that could produce nice pitches that are stable over time while also consuming less time than a marimba.

To be honest, I don't really know why some tuners can't pick up some instruments even when they play loudly enough. It may be due to overtones of the instrument interfering with the tuner's measurement of the fundamental. Resonator pipes, as in a marimba, might reduce interference. You could also carve off the bottom of the bars so they are shaped like arches instead of boxes to get nice integer-multiple harmonics, but this may not be best for you in terms of time since you said you want plenty of time for you other events. And of course, since I don't know why tuners fail for some instruments, this paragraph could be completely wrong.
I ❤ sounds of music! About meRate my tests
Physics and biology events

UNC-Chapel Hill ’23

User avatar
Nydauron
Member
Member
Posts: 22
Joined: March 20th, 2018, 8:10 pm
Division: Grad
State: IL
Location: Cornfields...

Re: Sounds of Music C

Postby Nydauron » October 15th, 2019, 12:39 pm

In my opinion, based on this year's rules, a string instrument would be one of the more ideal instruments since you can tune each individual string right before the pitch test just by changing the tension. With wind instruments, tuning each note is super difficult. For example, if your recorder goes out of tune for some reason, you basically have to file away at the hole or apply wax to raise or lower a note. It's a lot harder to tune an individual pitch on-the-spot.
I'm definitely out of place here, but someone of my team built a violin last year. So there's an idea, I guess.
Honestly, creds to him/her for trying to build this. However, even with this year's rules where sound intensity isn't included in the score, building a violin seems too risky. When doing your pitch test, it is going to be really hard to get precise results on the pitch test. Furthermore, even if you are using a fingering chart or tapes on the fingerboard, you are relying on only your perception of the note to determine if it is within the range of cents. Take it from me; I've played the violin for 13 years so I would know plenty on all the intonation issues I've made...
Conant 19'
UIUC 23'
Member of The Builder Cult
2018 State - 2nd MTV | 3rd Hovercraft
2019 State - 5th MTV | 5th Sounds
Physics is the only real science
Change my mind

Userpage

UsernameUsername
Member
Member
Posts: 1
Joined: November 12th, 2019, 6:34 am
Division: C
State: IL

Re: Sounds of Music C

Postby UsernameUsername » November 12th, 2019, 7:37 am

I have a Xylophone as my instrument and it is quiet. I would need the microphone to be half and inch away from my instrument for it to register . Should I tell the event supervisor during the pitch test that I need the microphone right next to the instrument? I know that the rules say it can be as close as necessary, but I am wondering if I should advise the event supervisor that I need it that close.
Fox Homeschoolers
2020 events Sounds of Music, Circuit Lab, Ping Pong Parachute, Machines.

User avatar
gz839918
Member
Member
Posts: 71
Joined: April 27th, 2019, 6:40 pm
Division: Grad
State: NC

Re: Sounds of Music C

Postby gz839918 » November 12th, 2019, 5:30 pm

I have a Xylophone as my instrument and it is quiet. I would need the microphone to be half and inch away from my instrument for it to register . Should I tell the event supervisor during the pitch test that I need the microphone right next to the instrument? I know that the rules say it can be as close as necessary, but I am wondering if I should advise the event supervisor that I need it that close.
Heyo! I believe your team is planning on going to the Raymond Park Invitational, and I'll be your sounds of music event supervisor there. On invitational day, I'd be happy to move the microphone as close as you need it. To answer your question generally, what's stopping you from telling your supervisor that? You're welcome to tell your supervisors about anything you need. (That doesn't mean they have to grant your request, but in this case, the rules are specifically on your side.) For something as vital as getting your pitches to register, then ask away!

The thing I'd be worried about though is that you don't know what type of microphone your supervisor will use. For example, what if my microphone just happens to be lower quality than the microphone you used when you were testing—and as a result, it just so happens that my microphone can't pick up the xylophone, no matter how close it is? Or what if I accidentally drop the microphone, and suddenly it has trouble picking up softer sounds? It may be a safer bet just to keep working on your instrument so that you're sure it has enough intensity, because you can't always tell the specifications of the equipment at the tournament.
I ❤ sounds of music! About meRate my tests
Physics and biology events

UNC-Chapel Hill ’23

Doctheduck
Member
Member
Posts: 2
Joined: October 5th, 2019, 10:11 am
Division: C
State: MT

Re: Sounds of Music C

Postby Doctheduck » December 12th, 2019, 12:40 pm

This year my partner and I a slidable drum type thing, sort of like a drum and trombone combined. It registered all of the pitches quite well and we were able to place 1st at states with it :D (In MT obviously so maybe not the toughest competition)

wec01
Member
Member
Posts: 220
Joined: February 22nd, 2019, 4:02 pm
Division: Grad
State: VA

Re: Sounds of Music C

Postby wec01 » December 12th, 2019, 1:13 pm

This year my partner and I a slidable drum type thing, sort of like a drum and trombone combined. It registered all of the pitches quite well and we were able to place 1st at states with it :D (In MT obviously so maybe not the toughest competition)
Congrats! That sounds like a cool instrument.
2019 Division C Nationals Medals:
4th place Fossils
5th place Sounds of Music
2nd place Thermodynamics

bryan,boyd
Member
Member
Posts: 7
Joined: October 28th, 2018, 3:38 pm

Re: Sounds of Music C

Postby bryan,boyd » December 18th, 2019, 1:04 pm

Does anyone have any good resources to study about FFT and how different graphs relate to different instruments?
2018 Events: Fermi Questions, Game On, Helicopters, Mousetrap Vehicle, Write It Do It, Duct Tape Challenge
2019 Events: Fermi Questions, Circuit Lab, Sounds of Music, Wright Stuff

User avatar
gz839918
Member
Member
Posts: 71
Joined: April 27th, 2019, 6:40 pm
Division: Grad
State: NC

Re: Sounds of Music C

Postby gz839918 » December 20th, 2019, 1:58 pm

Does anyone have any good resources to study about FFT and how different graphs relate to different instruments?
If you haven't already, I'd recommend watching this YouTube video on Fourier Transforms. The fast Fourier Transform is pretty much just a special algorithm for computing the Fourier Transform for a discrete set of sound data, and I wouldn't worry too much about the fine details.

If you're given a spectrum, spectrogram, impedance curve, or ADSR envelope of an instrument, I'm sorry to say that there's no really good way to figure out what instrument it is, unless it's a multiple-choice question where the wrong answers are clearly ridiculous.* Sadly, test writers can become a little petty in asking you to identify the instrument when much of the time an accurate identification isn't even possible.

*There are a few very rare instances where these questions are solvable, but only by by process of elimination. Here's an example question: this spectrum from the UNSW acoustics website was most likely produced by what instrument: a snare drum, a flute, or a xylophone? (ignoring the fact that the answer is in the image whoops lololol) Because all the peaks in the spectrum are equally spaced, you know the frequencies with the most energy must also be equally spaced—in other words, the overtone frequencies are equal to the fundamental frequency times a positive integer. This is only true for a flute, since the snare drum has no definite pitch, and xylophone overtones are equal to a square number times the fundamental frequency. It basically reduces to knowing how the instrument works, but if the instruments in the answer choices worked in a similar way, like a flute/recorder instead of flute/drum/xylophone, it'd truly be impossible to tell (of course provided I didn't tell you the answer in the question lol).

If there's a specific question you have from a test, feel free to post it here on the forums or message me, and I'd be happy to help you how I can! :D
I ❤ sounds of music! About meRate my tests
Physics and biology events

UNC-Chapel Hill ’23

Apple5775
Member
Member
Posts: 3
Joined: December 22nd, 2019, 11:30 am
Division: C

Re: Sounds of Music C

Postby Apple5775 » December 24th, 2019, 11:27 am

I'm a little confused on what notes our instrument needs to be able to play for Twinkle Twinkle.
When I first read the rules, I was going to make an instrument to play the scale F3, G3, A3, B♭3, C5, D5, E5, F5. I thought all of Twinkle Twinkle had to be within the skipped range so I was going to build the notes C4, D4, E4, F4, G4, A4 and start on C4. The only note I wouldn't have to build in the two octave scale is B♭4.

After some more reading, the device just needs to be able to play "additional pitches" (2 or more?) within the skipped range in order to get tested for the Song score.
In the rules the starting note for the song must be in the range "encompassed" by the pitch test scale. I would think encompassed means the whole two octaves, not the skipped range. This seems like I could play Twinkle using the notes F3, G3, A3, B♭3, C4, and D4. This includes 2 notes not in the pitch score ("additional pitches"), and is also less building.

Now the FAQ has completely confused me. One question assumes that the song must be in the "skipped range". The answer does not address this assumption. The FAQ says one can play notes in the pitch score as part of the song, but will also have to play some skipped pitches because the song "includes" these notes. One will end up playing pitches in the "skipped range " for most starting notes. However, using my example above, if one starts on C5, D5, E5, or F5, and builds even higher notes, the scale will not include "skipped pitches" and therefore is also not playing the required "additional pitches."

I know this isn't a place for official rule clarifications. Any thoughts on how many notes are needed and how people are interpreting the rules?

User avatar
Giantpants
Member
Member
Posts: 92
Joined: February 7th, 2019, 5:42 am
Division: C
State: NY

Re: Sounds of Music C

Postby Giantpants » December 24th, 2019, 1:26 pm

When I was initially building my instrument, I had a lot of internal debate on this too. I think your initial interpretation is right? You should be able to use F3-D4 for the song, considering C4 and D4 qualify as “additional pitches within the scale’s skipped range.” (Assuming additional means adding onto the scale lol)

That’s what I did, after all. My scale is C3, D3, E3, F3, G4, A4, B4, C5, and I made A3 and G3 so I could play the song in one octave, using “additional pitches within the skipped range.” Both comps I’ve been to so far have accepted this, so I think I’m good?

If anyone wants to corroborate what I’ve said by all means go for it, since this obviously is not an official ruling lol
President, Kellenberg, 2018-2020
Bro. Joseph Fox, 2014-2017

2020 Events: Dynamic Planet, Geologic Mapping, Sounds of Music, Astronomy


Return to “Lab Events”

Who is online

Users browsing this forum: No registered users and 1 guest