Overview
This lecture introduces musical intervals, covering their definitions, types (number and quality), naming conventions, and how to identify and alter intervals using major scales.
What Are Intervals?
- Intervals measure the distance between two notes in music.
- They help describe scales, chords, melodies, and are essential for sight-reading, singing, composition, and improvisation.
- Understanding major scales and key signatures is crucial for learning intervals.
Interval Numbers
- The interval number counts the letter names (A-G) from the lower to the upper note, including both.
- Accidentals (sharps/flats) do not affect the interval number.
- Examples: A to E is a fifth, C to C is an octave or unison, C to E is a third.
- Special names: unison (1st), octave (8th), fifteenth (2 octaves).
Interval Qualities
- Intervals are classified as perfect, major, minor, diminished, or augmented.
- Quality is determined by comparing the upper note to the major scale of the lower note.
- Perfect intervals: unison, fourth, fifth, octave (when both notes appear in the major scale).
- Major intervals: second, third, sixth, seventh (when both notes appear in the major scale).
Altering Interval Qualities
- Lowering a major interval by one semitone makes it minor.
- Lowering a major interval by two semitones makes it diminished.
- Raising a major interval by one semitone makes it augmented.
- Perfect intervals can only be diminished (one semitone smaller) or augmented (one semitone larger).
- There are no minor versions of perfect intervals.
How to Determine Interval Quality
- Compare the upper note to the major scale built on the lower note.
- If the upper note isn't in the major scale, use the alteration rules for minor, diminished, or augmented intervals.
Key Terms & Definitions
- Interval — The distance between two musical notes.
- Major Scale — A diatonic scale with a specific pattern of whole and half steps.
- Perfect Interval — Unison, fourth, fifth, or octave in the major scale.
- Major Interval — Second, third, sixth, or seventh in the major scale.
- Minor Interval — Major interval lowered by one semitone.
- Diminished Interval — Major/Perfect interval lowered by two (major) or one (perfect) semitones.
- Augmented Interval — Major/Perfect interval raised by one semitone.
- Unison — Two notes of the same pitch.
Action Items / Next Steps
- Review and practice identifying intervals on the staff using major scales.
- Prepare for part two: intervals larger than an octave, handling non-major bottom notes, and inversions.