Intervals
An interval is the distance between two notes. Every name you'll meet for one is in the chart: the old Latin name of the scale degree, the short name players say ("a minor 3rd", m3), the solfège syllable, the chord numeral and the number against the major scale. Press a column to hear it; a song for each one makes it stick.
The Roman numerals are the chords of the major key on the degrees that belong to it (vii° is diminished). The solfège is movable do with the chromatic syllables: ra, me, se, le, te for the lowered notes.
Augmented 4th / Diminished 5th A4 / d5
Up Down Together6 half steps Β· from A to D♯ (or E♭)
The tritone: half an octave, restless and unresolved, the sound of a dominant 7th's tension.
Remember it by
The Simpsons Theme Β· Danny Elfman ↑ up
Listen for "The Simp-" (the choir's first two notes).