# Tuning

An item that contains information for tuning an instrument.

### Description

A tuning item contains information for converting MIDI pitch numbers to frequency for an instrument or template. The information includes an array of frequencies, and 32-bit integer values indicating the number of pitches, notes in an octave, and the lowest pitch for the tuning frequency. See the CreateTuning`()` call in the "Audio folio Calls" chapter in this manual for more information.

### Folio

audio

### Item Type

AUDIO_TUNING_NODE

### Create

`CreateItem()`

`CreateTuning()`

### Delete

`DeleteItem()`

`DeleteTuning()`

### Query

None

### Modify

`SetAudioItemInfo()`

### Use

`TuneInsTemplate()`

`TuneInstrument()`

### Tags

AF_TAG_ADDRESS
  (const ufrac16 *) Create, Modify. Array of frequencies in 16.16 Hz to be used as a lookup table.

AF_TAG_BASENOTE
  (uint32) Create, Modify. MIDI note number that should be given the first frequency in the frequency array in the range of 0..127.

AF_TAG_FRAMES
  (uint32) Create, Modify. Number of frequencies in array pointed to by AF_TAG_ADDRESS. This value must be >= NotesPerOctave.

AF_TAG_NOTESPEROCTAVE
  (uint32) Create, Modify. Number of notes per octave. This is used to determine where in the frequency array to look for notes that fall outside the range of BaseNote..BaseNote+Frames-1. This value must be <= Frames.