Function chordFromSpec

chordFromSpec(spec: ChordSpec): ChordData
Build a chord from a ChordSpec.

The structural way in, for the chords a quality name cannot reach: the tones come from the spec, and quality is the name that fits it, or the nearest name when none does. A chord built this way is an ordinary Chord — every consumer reads its intervals as before, and formatChordSymbol writes the alterations back out.
Parameters
- spec: ChordSpec
  The chord spec; its rootPc/bassPc become the chord's.
Returns ChordData
The constructed chord.
Throws
If any part of the spec is not one the model defines.
Example
```
import { chordFromSpec } from '@libraz/libcantus';
chordFromSpec({
  rootPc: 0,
  base: 'maj',
  seventh: 'maj7',
  alterations: [{ degree: 11, alter: 1 }],
  additions: [],
  omissions: [],
});
// { rootPc: 0, quality: 'maj7#11', intervals: [0, 4, 7, 11, 18] }
```
- Defined in src/theory/chord/index.ts:298