Function chordSpecOf

chordSpecOf(chord: ChordData): ChordSpec
Read a chord structurally: which base, seventh, alterations and omissions it is made of.

The reading comes from the tones themselves, so it describes a chord whatever built it — a parsed symbol, a detected pitch set, a span carrying a template no name covers. Only a template with no structural reading at all falls back to the one its quality names.
Parameters
- chord: ChordData
  The chord to read.
Returns ChordSpec
The spec, carrying the chord's own root and slash bass.
Throws
If the chord's template has no reading and its quality is unknown.
Example
```
import { chordSpecOf, parseChordSymbol } from '@libraz/libcantus';
chordSpecOf(parseChordSymbol('C7(b9,#11)')).alterations;
// [{ degree: 9, alter: -1 }, { degree: 11, alter: 1 }]
```
- Defined in src/theory/chord/index.ts:333