Re: Sounds of Music C
Posted: February 21st, 2020, 9:01 pm
Do you guys have any recommendations on where to find information of how to do the math equations on the written portion? Thanks!
I need help with this questionA string under tension is found to produce a frequency of 200 Hz when plucked. If the
tension applied to the string is doubled, what frequency will it now produce?
Just as a heads up, this would have probably best if you asked on the question marathon. But I digress...
Using the equationsand
, we can substitute
in the second equation.
![]()
Simplified for sanity's sake... Looking at this new equation, if we double tension
and keep everything else constant,
must increase by a factor of
. Therefore, the answer is
or
.
dang algebra. thanks! ill put my questions in the marathon next time. wasnt sure if i should since i wouldnt be able to explain the answerNydauron wrote: ↑February 27th, 2020, 6:41 pmJust as a heads up, this would have probably best if you asked on the question marathon. But I digress...Here is the answer:
Using the equationsand
, we can substitute
in the second equation.
![]()
Simplified for sanity's sake... Looking at this new equation, if we double tension
and keep everything else constant,
must increase by a factor of
. Therefore, the answer is
or
.
The aural section of the MIT test was done very similarly to the AP Music Theory test.glin1011 wrote: ↑March 7th, 2020, 7:02 am Just a random question, wondering if it helps anyone:
Is it worth it to listen to a few classical music compositions for the competition? I know one test was an auditory one and I was wondering if it was appropriate to listen a few, especially when it comes to reading the music sheets.
Update to this: if you're an event supervisor and you're using a Neewer microphone (the microphone recommended by SO Inc.), then Audacity will not work. Even if the microphone is working for literally everything else, including pascioly.org and Praat, it won't work with Audacity. On my Windows 10 Dell Inspiron laptop, I tested pascioly.org and Praat and Audacity one by one, and only Audacity would default to the built-in microphone on the computer while the others would pick up from the Neewer. I don't actually have an answer for why so enjoy the smiling shrug person instead ¯\_(ツ)_/¯gz839918 wrote: ↑February 11th, 2020, 4:25 pm At the two invitationals where I supervised, I used the pascioly.org applet whenever it could register the note, and I used Audacity as a backup. Audacity offered several advantages for use as a backup:
Disadvantages of Audacity include...
- It records anything. The pascioly.org web app did not read notes that were too silent, and without Audacity, some teams would have had to receive a skipped note even if I could hear a clear distinct pitch.
- I have control over analyzing pitch. pascioly.org is a black box with nuts and bolts I can't see. if pascioly.org suddenly jumps to a cents-off reading before returning to no note detected, I can't always tell whether the web app suddenly started working again, or whether its invisible internal machinery set off a false alarm by giving me an incorrect reading (for example, because of a spike in background noise).
I prefer the pascioly.org web app over Audacity whenever I have a professional microphone, but since I can always see the raw waveform in Audacity, it helps if pascioly.org isn't working. I would discourage Audacity to event supervisors except as a backup. Another possible backup method which I haven't tried out is to use cell phone microphones with a tuning app. These days, even cell phone microphones are legit actually quite good.
- Audacity rounds fundamental and overtone frequencies to the nearest integer, which is not super great since several notes may be spaced within only a few hertz, and so this may increase the cent difference. Case in point, E3 and F3 are only 10 Hz away, and if Audacity rounds up by 1 Hz to the nearest integer, that could increase a team's cents error by around 10 cents for that note.
- Audacity can't discern when the frequency is not equal to the pitch, such as when partials move but spectral envelope (overall shape of the spectrogram) is unchanged. This problem is very rare for strings and pipes however, and I think I saw it only once.
- In some idiophones, there's no clear apparent pattern amongst partials. So what the heck do I measure? (I usually chose whatever peak frequency was closest to the target note, but due to the bullet point above, I know this wasn't a great idea because it resulted in huge cent differences from the target note. My reasoning was that it was better than giving teams zero points when pascioly.org stopped working.)
Not specific to Audacity though, many compelling reasons exist for why pitch shouldn't be measured as the fundamental frequency. These issues could occur with the pascioly.org web app too; some supervisors simply choose to ignore the measured values and wait until pascioly.org displays the pitch they want it to display.