Scioly.org

mjcox2000 wrote:1. What is a pedal tone?
2. On which instruments can a pedal tone be played?
3. Is a pedal tone in the instrument’s harmonic series? Is it a resonant frequency for the instrument? What tradeoffs do instrument designers make relating to pedal tones?
4. Would a player be more likely to play pedals when warming up or warming down? Why?

1. A special low note/the first partial
2. Brass instruments
3. The pedal tone is at the fundamental frequency of the instrument's harmonic series, however instrument designers make the bell and mouthpiece so that rather than playing all of the odd harmonics, the instrument plays all of the harmonics besides the fundamental, so the pedal tone is not a resonant frequency.
4. I'm not sure but maybe warming up because the instruments go sharp when they get warmer.

wec01 wrote:

mjcox2000 wrote:1. What is a pedal tone?
2. On which instruments can a pedal tone be played?
3. Is a pedal tone in the instrument’s harmonic series? Is it a resonant frequency for the instrument? What tradeoffs do instrument designers make relating to pedal tones?
4. Would a player be more likely to play pedals when warming up or warming down? Why?

Answers (Click to Show Hidden Text)

1. A special low note/the first partial
2. Brass instruments
3. The pedal tone is at the fundamental frequency of the instrument's harmonic series, however instrument designers make the bell and mouthpiece so that rather than playing all of the odd harmonics, the instrument plays all of the harmonics besides the fundamental, so the pedal tone is not a resonant frequency.
4. I'm not sure but maybe warming up because the instruments go sharp when they get warmer.

Warm down because it restores blood flow to the lips.

wec01 wrote:List the seven church modes, their relation to either the major or natural minor scales (e.g. natural minor with a raised 6th), and what note they start on given there are no sharps or flats (e.g. the major scale with no sharps or flats starts on C).

Ionian - Major scale, C

Dorian - Minor scale with a raised 6th, D

Phrygian - Minor scale with a lowered 2nd, E

Lydian - Major scale with a raised 4th, F

Mixolydian - Major scale with a lowered 7th, G

Aeolian - MInor scale, A

Locrian - Minor scale with a lowered 2nd and 5th, B

UTF-8 U+6211 U+662F wrote:

wec01 wrote:List the seven church modes, their relation to either the major or natural minor scales (e.g. natural minor with a raised 6th), and what note they start on given there are no sharps or flats (e.g. the major scale with no sharps or flats starts on C).

Click to Show Answer

Ionian - Major scale, C

Dorian - Minor scale with a raised 6th, D

Phrygian - Minor scale with a lowered 2nd, E

Lydian - Major scale with a raised 4th, F

Mixolydian - Major scale with a lowered 7th, G

Aeolian - MInor scale, A

Locrian - Minor scale with a lowered 2nd and 5th, B

UTF-8 U+6211 U+662F wrote:Why do the harmonics of a closed-end pipe differ from the harmonics of a pipe open at both ends?

On an open pipe with no end corrections, both the ends are the locations of nodes in the sine wave being produced. However, on a closed pipe, the closed end is an antinode, so there is a quarter of a standing wave at the closed end instead of half a standing wave at each end like on an open pipe. This extra fraction of a standing wave prevents the production of even harmonics.

smayya337 wrote:

UTF-8 U+6211 U+662F wrote:Why do the harmonics of a closed-end pipe differ from the harmonics of a pipe open at both ends?

Answer... I think (Click to Show Hidden Text)

On an open pipe with no end corrections, both the ends are the locations of nodes in the sine wave being produced. However, on a closed pipe, the closed end is an antinode, so there is a quarter of a standing wave at the closed end instead of half a standing wave at each end like on an open pipe. This extra fraction of a standing wave prevents the production of even harmonics.

UTF-8 U+6211 U+662F wrote:

smayya337 wrote:

UTF-8 U+6211 U+662F wrote:Why do the harmonics of a closed-end pipe differ from the harmonics of a pipe open at both ends?

Answer... I think (Click to Show Hidden Text)

On an open pipe with no end corrections, both the ends are the locations of nodes in the sine wave being produced. However, on a closed pipe, the closed end is an antinode, so there is a quarter of a standing wave at the closed end instead of half a standing wave at each end like on an open pipe. This extra fraction of a standing wave prevents the production of even harmonics.

Can you explain why there are nodes and antinodes there too?

At the ends of a pipe, the pressure of the air inside the pipe needs to equalize with the pressure of the atmosphere, hence the location of nodes there. This isn't necessary at a closed end, as the pressure of the air is already equal to the pressure on the other end (e.g. a clarinetist blowing into their instrument - the pressure at the mouth and inside the instrument are equal).

smayya337 wrote:

UTF-8 U+6211 U+662F wrote:

smayya337 wrote:

Answer... I think (Click to Show Hidden Text)

On an open pipe with no end corrections, both the ends are the locations of nodes in the sine wave being produced. However, on a closed pipe, the closed end is an antinode, so there is a quarter of a standing wave at the closed end instead of half a standing wave at each end like on an open pipe. This extra fraction of a standing wave prevents the production of even harmonics.

Can you explain why there are nodes and antinodes there too?

Don't know if I should hide this but I did anyway (Click to Show Hidden Text)

At the ends of a pipe, the pressure of the air inside the pipe needs to equalize with the pressure of the atmosphere, hence the location of nodes there. This isn't necessary at a closed end, as the pressure of the air is already equal to the pressure on the other end (e.g. a clarinetist blowing into their instrument - the pressure at the mouth and inside the instrument are equal).