Open-string MIDI pitch per string, lowest-sounding string first.
Highest fret number; fret 0 is the open string.
Greatest fret span one hand can hold down at once.
Optionalfretless?: booleanThe neck has no frets. Positions are continuous, so intonation is the player's and a slide is unbroken; in twelve-tone equal temperament the positions coincide with fret numbers, so range and stretch are read the same way.
A fretted or fretless string instrument, described by what it is rather than by the range it happens to have.
The sounding range follows from
tuningandfrets: stringssoundstuning[s] .. tuning[s] + frets. Storing[min, max]instead would make a five-string bass, a drop tuning, a seven-string guitar and an extended-range neck four unrelated special cases, and would leave "the neck is not long enough" indistinguishable from "the note is below the instrument".