Function spellAugmentedSixth

spellAugmentedSixth(kind: AugmentedSixthKind, tonic: NoteLike): NoteData[]
Spell an augmented-sixth chord from a spelled tonic, lowest note first.

This is the spelled counterpart of augmentedSixthChord, and the table the chord's own spelling is built from: every tone is placed by a named interval above the bass, so the outer interval is an augmented sixth in every key rather than the minor seventh its ten semitones would otherwise imply. Reach for it when a spelled tonic is all there is; spelling the chord itself with spellChord names the same notes, in the chord's own order.

A tonic carrying an octave yields notes carrying octaves, ascending from the bass; an octave-less tonic yields octave-less notes.
Parameters
- kind: AugmentedSixthKind
  Which of the three augmented sixths to spell.
- tonic: NoteLike
  The spelled tonic of the key, as a note name, a MIDI number, note data, or a Note.
Returns NoteData[]
The spelled tones, bass first and ascending.
Throws
If kind is not one of the three, or tonic is not a note.
Example
```
import { noteNames, parseNote, spellAugmentedSixth } from '@libraz/libcantus';
noteNames(spellAugmentedSixth('german', parseNote('C'))); // ['Ab', 'C', 'Eb', 'F#']
noteNames(spellAugmentedSixth('italian', 'E')); // ['C', 'E', 'A#']
```
- Defined in src/analyze/functional/augmented-sixth.ts:372