Sight-Singing & Melodic Dictation #18: May 1 - 7 *challenge*

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Today is the last week for sight-singing and melodic dictation!!! The AP exam is on the 8th, so this should be more than enough preparation up until that last day of cramming! Good luck to all!

Sight-Singing & Melodic Dictation #17: Apr 24 - 30

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #16: Apr 17 - 23

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #15: Apr 10 - 16

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #14: Apr 3 - 9

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #13: Mar 27 - Apr 2

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #12: Mar 20 - 26

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #11: Mar 13 - 19

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #10: Mar 6 - 12

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long. Sorry for the lateness!

Sight-Singing & Melodic Dictation #9: Feb 27 - Mar 5

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #8: Feb 20 - 26

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #7: Feb 13 - 19

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #6: Feb 6 - 12

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #5: Jan 30 - Feb 5

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #4: Jan 23 - 29

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #3: Jan 16 - 22

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

*Note* I apologize for the lateness of this video! I was having some technical difficulties which slowed the processing of the video. The weekly schedule should resume on Monday.

Sight-Singing & Melodic Dictation #2: Jan 9 - 15

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

Sight-Singing & Melodic Dictation #1: Jan 2 - 8

(L) Practice for the AP exam! I will be releasing a video every Monday for a semester (18 weeks): 14 melodies, 7 pairs. Each pair has a song in treble or bass, major or minor, 4/4 or 6/8, and each 4 measures long.

APMT #2: PRACTICE

Here are some practice questions that go with the second episode. Watch the video first then answer the questions below.

Question 1: Label and define the parts of the diagram below.


Question 2: Assuming the scales of the images below are the same, which wave has the largest volume? Which one has the smallest volume?


Question 3: Listen to the audio file. Describe what is happening to the frequency and amplitude over time.

Audio file:


Question 4: What is the formula used to depict sound waves, including pitch and volume?


Question 5: What unit is the y-axis measured in?


For questions 6 and 7, use the graphs to find the amplitude of the sound depicted (hint: use the parent function and solve for the missing variable).
Question 6:


Question 7:


For questions 8 and 9, use the graphs to find the pressure difference of the sound depicted at 4.2 seconds. For 9, round the calculated frequency to the nearest whole number.
Question 8:


Question 9:


For question 10, use the graph to find 3 times between .4 and .5 seconds where the pressure difference is -1.909.
Question 10:


Explanations are now included in the answers.

Answer 1: Top answer: compression. A compression is an area where the particles are closest together. Bottom answer: rarefaction. A rarefaction is an area where the particles are furthest apart.
Answer 2: Largest volume: blue. This is because the amplitude is the largest. Smallest volume: orange. This is because the amplitude is the smallest.
Answer 3: The frequency remains constant, while the amplitude decreases. The amplitude decreases because the volume decreases.
Answer 4: y = A * sin(2 * pi * frq * x). A is the new value added in from the last video.
Answer 5: N/m^2, or Pascals.
Answer 6: A = 2.5. We first plug the point given into the parent function. Also, it is apparent on the graph that the frequency is 1, so we plug that in too: -1.177 = A * sin(2 * pi * 1 * 1.578). Isolate A by dividing both sides by sin(2 * pi * 1 * 1.578), getting 2.5.
Answer 7: A = 3.7. To go about solving this problem, simply reference the problem above. The only real difference is that the frequency is not 1; it is 5.
Answer 8: Pressure difference = 0. When asking for pressure difference, we must find the y value. In our equation, have 3 variables: A, frq, and x. X is given; it's 4.2. A is visible; it's 4. Frq is also visible, to an extent; in .2 seconds, there are 3 periods, so the frequency is 15 Hz. Plug these in and solve for y.
Answer 9: Pressure difference = -1.705. This one is a bit more tricky. We still need to solve for y, but the variables A and frq are not as clear. To find A, just look at the point given; it's at the peak, so A is the y value, 2.9. Now we have to find frq. There are two ways we can go about find it. First, we notice that the x value is given at halfway through the crest. By multiplying it by 4, we know the x value at the end of the trough, or the complete period. There is 1 period in .02632 seconds, so there are 38 periods in 1 second (that's the frequency). The second method^† is plugging the point into the function. 2.9 = 2.9 * sin(2 * pi * frq * .00658), so divide both sides by 2.9. 1 = sin(2 * pi * frq * .00658), now inverse-sine both sides (it looks like sin^-1 on your calculator). This cancels out the sin part, giving us 1.5708 = 2 * pi * frq * .00658. Solve for frq, getting 38. Now with our frequency, we plug it into our function with our desired x value (4.2) in mind: y = 2.9 * sin(2 * pi * 38 * 4.2).
Answer 10: .4122, .4628, and .4955 seconds. This problem is the toughest yet. As you know, the sine function is not one-to-one, meaning that for every y value, there may be multiple x values (in this case, infinitely many). We are asked to limit them to just three. To begin this problem, first find an x value that produces the desired y value—with this, we can find 3 others that happen to fall into the range we want. We need to solve for x, but we need the other variables first; the y is given, -1.909. The amplitude is observable, 6. The frequency is also observable, 12. -1.909 = 6 * sin(2 * pi * 12 * x), solving for x and getting roughly -.0043. What other x values can give us the same value? Well, a period over can; add the length of a period to this number to find a number in our range. If the frequency (cycles/second) is 12, then a period length is 1/12, or .0833. We add this multiple times to our calculated x value getting .0790, .1623, .2456... and eventually .4122 (let's call this point 1) and .4955 (point 2)! Both of those work, but the question asks for three x values, not two. If we look at the graph, we can see there's another point mirroring the trough on which .4955 is placed. We have to think using common sense here; a period consists of a trough and a crest. Divide that by two and we get the length of just one. So then, the length of a trough is .0417, using our previously calculated period length. Subtract that from .5 and we get the left side of the trough's x value, .4583. The difference between the right side of the trough (.5) and point 2 is .0045, so the difference between the left side of the trough and point 3 must be the same, making point 3 .4583 + .0045, or .4628.

^†Note that this method does not always work. If the point were given on a different crest—say, the second or third one—then another wave with a different frequency would be able to produce the same point, only it would be the first crest for that said wave. Click here to see a visual example.

APMT #2: Volume, part 1: Pressure and Modeling

(L) Again, not on the exam, but a good scientific introduction to sound. Eventually I'll get into the music stuff, but the way music and science combine is fun to study. In this episode, the physics behind volume is discussed.