Musical intervals, scales, and chords

Question 1

Standard musical intervals

Answer 1

Pairs of tones whose frequencies have a specific ratio

Question 2

Octave ratio

Answer 2

2/1

Question 3

P5 ratio

Answer 3

3/2

Question 4

P4 ratio

Answer 4

4/3

Question 5

M3

Answer 5

5/4

Question 6

m3

Answer 6

6/5

Question 7

M6

Answer 7

5/3

Question 8

Tone

Answer 8

9/8
Up a fifth, down a fourth

Question 9

Octave

Answer 9

Notes separated by an octave are perceived to be almost the same even though the pitches are different

Question 10

Why do notes with simple frequency ratios sound harmonious together?

Answer 10

We are used to hearing them together as part of the harmonic series of a certain tone

They have harmonics that either line up perfectly or are well separated (avoids dissonance of closely separated pure tones)

Question 11

Scales

Answer 11

Certain collections of notes within an octave, built from simple intervals

Question 12

Circle of fifths

Answer 12

A sequence of notes obtained by going up a fifth each time

Question 13

Pentatonic scale

Answer 13

Scale composed of the first five notes in the circle of fifths

Question 14

Major scale

Answer 14

Scale composed of the first seven notes in the circle of fifths

Question 15

Chromatic scale

Answer 15

Scale composed of the collection of 12 notes from the circle of fifths (13th is almost the same as the first)

Question 16

Equal tempered chromatic scale

Answer 16

Standard in Western music

Divides the octave into 12 equal intervals (semitones)

Each semitone corresponds to a frequency ratio of 2 to the power of 1/12 (1.05946)

Question 17

Just tuning

Answer 17

Intervals, scales, and chords defined based on whole number frequency ratios

Question 18

Equal-tempered tuning

Answer 18

Intervals, scales, and chords defined based on the equal division of the octave into 12 parts

Allows the same music to be played starting on any note