Overview
This lecture introduces musical intervals, explains how to measure and name them, describes interval families, and covers interval inversion. The lesson emphasizes practical identification skills for intervals within an octave.
Types of Intervals
- Intervals measure the distance between two pitches.
- Melodic intervals occur when notes are played in succession; harmonic intervals are notes played together.
- Simple intervals are an octave or smaller; compound intervals are larger than an octave but can be reduced to simple intervals for analysis.
Measuring Intervals
- Intervals have two components: generic size (number of staff lines/spaces spanned) and specific size (quality).
- Generic size does not change with clef or accidentals.
- Specific size is described with five adjectives: diminished, minor, perfect, major, and augmented.
Interval Families
- Family 1 (unisons, fourths, fifths, octaves): can be diminished, perfect, or augmented.
- Family 2 (seconds, thirds, sixths, sevenths): can be diminished, minor, major, or augmented.
- Family 1 intervals never have "minor" or "major"; Family 2 intervals never have "perfect."
Determining Specific Size
- Counting semitones can identify interval quality, but using scales is more practical.
- For Family 1: if the upper note is in both major and minor scales of the lower note, the interval is perfect; otherwise, modify perfect (augmented/diminished).
- For Family 2: if the upper note is in the major scale, the interval is major; if only in the minor scale, it's minor; otherwise, modify (augmented/diminished).
- Matched accidentals in fourths and fifths usually indicate a perfect interval, except for B-F.
Interval Inversion
- Inverting an interval swaps the upper and lower notes.
- When inverted: augmented ↔ diminished, major ↔ minor, perfect remains perfect.
- Interval numbers add up to 9 when inverted (e.g., third ↔ sixth).
- Use inversion to simplify identifying large intervals.
Key Terms & Definitions
- Interval — the distance between two pitches.
- Melodic Interval — two notes played in succession.
- Harmonic Interval — two notes played together.
- Simple Interval — interval of an octave or less.
- Compound Interval — interval larger than an octave.
- Generic Size — the basic interval size based on staff position.
- Specific Size — interval quality (diminished, minor, perfect, major, augmented).
- Inversion — swapping the top and bottom notes of an interval.
Action Items / Next Steps
- Practice identifying, spelling, and inverting simple intervals.
- Prepare for the next lesson on chords, focusing on triads.