qmk_firmware/keyboards/contra/keymaps/basic_qwerty/config.h

// Copyright 2021 Stehpon Parker (@stephondoestech)
// SPDX-License-Identifier: GPL-2.0-or-later

#pragma once


#ifdef AUDIO_ENABLE
    #define STARTUP_SONG SONG(PLANCK_SOUND)
    // #define STARTUP_SONG SONG(NO_SOUND)

    #define DEFAULT_LAYER_SONGS { SONG(QWERTY_SOUND), \
                                  SONG(DVORAK_SOUND) \
                                }
#endif

#define MUSIC_MASK (keycode != KC_NO)

/*
 * MIDI options
 */

/* enable basic MIDI features:
   - MIDI notes can be sent when in Music mode is on
*/

#define MIDI_BASIC

/* enable advanced MIDI features:
   - MIDI notes can be added to the keymap
   - Octave shift and transpose
   - Virtual sustain, portamento, and modulation wheel
   - etc.
*/
//#define MIDI_ADVANCED