The minor 2nd on the guitar
1 semitone · m2 · C → D♭
Its character, in the app's words: anxiety; an octave wider (m9), anguish: the tension gains space.
The shapes on the neck
- On the same string: 1 fret up.
- On the next string, towards the 1st: 4 frets back; 3 frets back when you cross from the G string to the B string, which are tuned a major 3rd apart instead of a 4th.
- Turned upside down it becomes a major 7th: 1 + 11 = 12 semitones.
The root is the C on the A string, 3rd fret; the other circles are the same note, D♭, wherever it sits between frets 0 and 12. The 1st string (high e) is at the top, as in the app. The root is filled.
Open it in the app: 2. Intervals
The other intervals