An interval is the distance between two notes, counted in half steps. Each distance has a name and a song that opens with it. Pick a root, then play every distance from it, one after the other or together.
Every row plays its interval from the root you pick. The song is the memory hook: hear the interval, hear the song start.
Root
How it plays
C → C♯ · 1 half step · the Jaws creepC → D · 2 half steps · Happy Birthday's first two notesC → D♯ · 3 half steps · Greensleeves' opening leapC → E · 4 half steps · Oh, when the saints…C → F · 5 half steps · Here comes the brideC → F♯ · 6 half steps · The Simp-sonsC → G · 7 half steps · Twinkle, twinkleC → G♯ · 8 half steps · The Entertainer's big leapC → A · 9 half steps · My Bonnie lies over the oceanC → A♯ · 10 half steps · the Somewhere leapC → B · 11 half steps · Take On Me, up into the chorusC → C · 12 half steps · Somewhere over the rainbow
Rough or smooth
Close intervals beat and clash; wider ones ring. The half step is the roughest sound in the scale, the fifth and octave the smoothest. Compare on your chosen root: