42 LearnMusicTheory.net High-Yield Music Theory, Vol. 1: Music Theory Fundamentals Section 3.1 I NTRODUCTION TO I NTERVALS Interval An interval is the pitch distance (high-low distance) between two notes. definition Interval names have two parts: 1. The general category of the interval, based on counting the number of letter names using the starting letter name as number one; and 2. The quality of the interval, related to how many half steps are between the notes. Major and perfect Major and perfect quality intervals match the notes of a major scale, intervals starting from the first note of the scale up. Seconds, thirds, sixths, and sevenths can be major in quality, but never perfect. Unisons, fourths, fifths, and octaves (“8ves”) can be perfect in quality, but never major. C major scale with scale steps numbered: w & w w w w w w1 w2 3 4 5 6 7 8 I I I I I I I wI & w w w w w w1 - w1 w1 - w2 w1 - 3 w1 - 4 w1 - 5 w1 - 6 w1 - 7 w1 - 8 Half steps:(0) (2) (4) (5) (7) (9) (11) (12) Perfect Major Major Perfect Perfect Major Major Perfect Unison (PU) 2nd 3nd 4th 5th 6th 7th Octave (8ve) Minor intervals Minor intervals are one half step smaller than major intervals, keeping the same letter names. Only intervals that can be major are able to become minor: seconds, thirds, sixths, and sevenths only. Seconds: Thirds: & bw & nw & bw & nw Minorw second Majorw second Minorw third Majorw third Sixths:{ Sevenths:{ & bw & nw & bw & nw Minorw sixth Majorw sixth Minor wseventh Majorw seventh { { Chapter 3: Intervals and Transposition 43 Diminished Diminished intervals are one half step smaller than minor or perfect Augmented intervals, keeping the same letter names. Augmented intervals are one half step larger than major or perfect intervals, keeping the same letter names. Thirds (seconds, sixths, and sevenths are similar): & & & & ∫w bw nw #w Diminishedw third Minorw third Majorw third Augmentedw third { { _ Fourths (unisons, fifths, and octaves are similar): & bw & nw & #w Diminishedw fourth Perfectw fourth Augmentedw fourth { _ Consonant Consonant intervals are intervals that sound more stable because of the intervals closer relationship between the physical vibration patterns of the notes. The closest relationships (and therefore the most stable intervals) are the Perfect, imperfect perfect consonances: perfect unison, perfect fifth, and perfect octave. The consonances imperfect consonances are major and minor thirds and sixths. They are not as stable as perfect consonances, but more stable than dissonances. Dissonant The dissonant intervals are seconds and sevenths as well as all diminished intervals and augmented intervals. The notes in dissonant intervals have physical vibration patterns that are relatively unrelated to one another and are Perfect fourth therefore unstable when compared to consonances. The perfect fourth is sometimes considered a consonance and sometimes a dissonance, depending on style and musical context. Simple and Simple intervals are an octave or smaller. Compound intervals are larger compound than an octave. Compound intervals use the same quality names as their intervals simple counterparts (major, perfect, etc.). To convert from simple to compound, add 7. Example: 2nd + 8ve = 9th since 2 + 7 = 9. Perfect 8ve Major 10th Perfect 12th Major 14th Major 9th Perfect 11th Major 13th Perfect 15th w w w w w w w & w 8vew 8ve+w2nd 8ve+w3rd 8ve+w4th 8ve+w5th 8ve+w6th 8ve+w7th 8ve+w8ve .