diff --git a/keyboards/preonic/keymaps/mechmaster48/config.h b/keyboards/preonic/keymaps/mechmaster48/config.h
new file mode 100644
index 00000000000..208d7abdbce
--- /dev/null
+++ b/keyboards/preonic/keymaps/mechmaster48/config.h
@@ -0,0 +1,46 @@
+/* Copyright 2021 mechmaster48
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+#pragma once
+
+#ifdef AUDIO_ENABLE
+ #define STARTUP_SONG SONG(PREONIC_SOUND)
+ // #define STARTUP_SONG SONG(NO_SOUND)
+
+ #define DEFAULT_LAYER_SONGS { SONG(QWERTY_SOUND), \
+ SONG(COLEMAK_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
diff --git a/keyboards/preonic/keymaps/mechmaster48/keymap.c b/keyboards/preonic/keymaps/mechmaster48/keymap.c
new file mode 100644
index 00000000000..ede37652381
--- /dev/null
+++ b/keyboards/preonic/keymaps/mechmaster48/keymap.c
@@ -0,0 +1,256 @@
+/* Copyright 2021 MechMaster48 admin@mechbox.net
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include QMK_KEYBOARD_H
+#include "muse.h"
+
+enum preonic_layers {
+ _QWERTY,
+ _LOWER,
+ _RAISE,
+ _ADJUST
+};
+
+enum preonic_keycodes {
+ QWERTY = SAFE_RANGE,
+ LOWER,
+ RAISE,
+ BACKLIT
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+/* Qwerty
+ * ,-----------------------------------------------------------------------------------.
+ * | Esc | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Tab | Q | W | E | R | T | Y | U | I | O | P | Del |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Caps | A | S | D | F | G | H | J | K | L | ; | Enter|
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | Shift| Z | X | C | V | B | N | M | , | . | / | " |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Ctrl | Alt | Gui | Brite |Lower | Space |Raise | Left | Down | Up |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_QWERTY] = LAYOUT_preonic_grid(
+ KC_ESC, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_BSPC,
+ KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_DEL,
+ KC_CAPS, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_ENT,
+ KC_LSFT, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_QUOT,
+ KC_LCTL, KC_LALT, KC_LGUI, BACKLIT, LOWER, KC_SPC, KC_SPC, RAISE, KC_LEFT, KC_DOWN, KC_UP, KC_RGHT
+),
+
+/* Lower
+ * ,-----------------------------------------------------------------------------------.
+ * | ~ | ! | @ | # | $ | % | ^ | & | * | ( | ) | Bksp |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | ~ | ! | @ | # | $ | % | ^ | & | * | ( | ) | Del |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | _ | + | { | } | | |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO ~ |ISO | | Home | End | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_LOWER] = LAYOUT_preonic_grid(
+ KC_TILD, KC_EXLM, KC_AT, KC_HASH, KC_DLR, KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_BSPC,
+ KC_TILD, KC_EXLM, KC_AT, KC_HASH, KC_DLR, KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_DEL,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12,S(KC_NUHS),S(KC_NUBS),KC_HOME, KC_END, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Raise
+ * ,-----------------------------------------------------------------------------------.
+ * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | Del |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | - | = | [ | ] | \ |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO # |ISO / | Pg Up| Pg Dn| |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_RAISE] = LAYOUT_preonic_grid(
+ KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_BSPC,
+ KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_DEL,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_MINS, KC_EQL, KC_LBRC, KC_RBRC, KC_BSLS,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_NUHS, KC_NUBS, KC_PGUP, KC_PGDN, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Adjust (Lower + Raise)
+ * ,-----------------------------------------------------------------------------------.
+ * | F1 | F2 | F3 | F4 | F5 | F6 | F7 | F8 | F9 | F10 | F11 | F12 |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | Reset| Debug| | | | |TermOf|TermOn| | | Del |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | | |Aud cy|Aud on|AudOff|AGnorm|AGswap|Qwerty| | | | |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | |Voice-|Voice+|Mus on|MusOff|MidiOn|MidOff| | | | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_ADJUST] = LAYOUT_preonic_grid(
+ KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12,
+ _______, RESET, DEBUG, _______, _______, _______, _______, TERM_ON, TERM_OFF,_______, _______, KC_DEL,
+ _______, _______, MU_MOD, AU_ON, AU_OFF, AG_NORM, AG_SWAP, QWERTY, _______, _______, _______, _______,
+ _______, MUV_DE, MUV_IN, MU_ON, MU_OFF, MI_ON, MI_OFF, _______, _______, _______, _______, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______
+)
+
+
+};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+ switch (keycode) {
+ case QWERTY:
+ if (record->event.pressed) {
+ set_single_persistent_default_layer(_QWERTY);
+ }
+ return false;
+ break;
+ case LOWER:
+ if (record->event.pressed) {
+ layer_on(_LOWER);
+ update_tri_layer(_LOWER, _RAISE, _ADJUST);
+ } else {
+ layer_off(_LOWER);
+ update_tri_layer(_LOWER, _RAISE, _ADJUST);
+ }
+ return false;
+ break;
+ case RAISE:
+ if (record->event.pressed) {
+ layer_on(_RAISE);
+ update_tri_layer(_LOWER, _RAISE, _ADJUST);
+ } else {
+ layer_off(_RAISE);
+ update_tri_layer(_LOWER, _RAISE, _ADJUST);
+ }
+ return false;
+ break;
+ case BACKLIT:
+ if (record->event.pressed) {
+ register_code(KC_RSFT);
+ #ifdef BACKLIGHT_ENABLE
+ backlight_step();
+ #endif
+ #ifdef RGBLIGHT_ENABLE
+ rgblight_step();
+ #endif
+ #ifdef __AVR__
+ writePinLow(E6);
+ #endif
+ } else {
+ unregister_code(KC_RSFT);
+ #ifdef __AVR__
+ writePinHigh(E6);
+ #endif
+ }
+ return false;
+ break;
+ }
+ return true;
+};
+
+bool muse_mode = false;
+uint8_t last_muse_note = 0;
+uint16_t muse_counter = 0;
+uint8_t muse_offset = 70;
+uint16_t muse_tempo = 50;
+
+bool encoder_update_user(uint8_t index, bool clockwise) {
+ if (muse_mode) {
+ if (IS_LAYER_ON(_RAISE)) {
+ if (clockwise) {
+ muse_offset++;
+ } else {
+ muse_offset--;
+ }
+ } else {
+ if (clockwise) {
+ muse_tempo+=1;
+ } else {
+ muse_tempo-=1;
+ }
+ }
+ } else {
+ if (clockwise) {
+ register_code(KC_PGDN);
+ unregister_code(KC_PGDN);
+ } else {
+ register_code(KC_PGUP);
+ unregister_code(KC_PGUP);
+ }
+ }
+ return true;
+}
+
+void dip_switch_update_user(uint8_t index, bool active) {
+ switch (index) {
+ case 0:
+ if (active) {
+ layer_on(_ADJUST);
+ } else {
+ layer_off(_ADJUST);
+ }
+ break;
+ case 1:
+ if (active) {
+ muse_mode = true;
+ } else {
+ muse_mode = false;
+ }
+ }
+}
+
+
+void matrix_scan_user(void) {
+#ifdef AUDIO_ENABLE
+ if (muse_mode) {
+ if (muse_counter == 0) {
+ uint8_t muse_note = muse_offset + SCALE[muse_clock_pulse()];
+ if (muse_note != last_muse_note) {
+ stop_note(compute_freq_for_midi_note(last_muse_note));
+ play_note(compute_freq_for_midi_note(muse_note), 0xF);
+ last_muse_note = muse_note;
+ }
+ }
+ muse_counter = (muse_counter + 1) % muse_tempo;
+ } else {
+ if (muse_counter) {
+ stop_all_notes();
+ muse_counter = 0;
+ }
+ }
+#endif
+}
+
+bool music_mask_user(uint16_t keycode) {
+ switch (keycode) {
+ case RAISE:
+ case LOWER:
+ return false;
+ default:
+ return true;
+ }
+}
diff --git a/keyboards/preonic/keymaps/mechmaster48/readme.md b/keyboards/preonic/keymaps/mechmaster48/readme.md
new file mode 100644
index 00000000000..8e2f9c11125
--- /dev/null
+++ b/keyboards/preonic/keymaps/mechmaster48/readme.md
@@ -0,0 +1,14 @@
+# OLKB Preonic Rev3 layout by mechmaster48
+
+- A simple layout largely based on the default with minor tweaks to fit my typing.
+- The esacpe key has been moved to the top left, ctrl and alt moved to bottom left, and enter key has been moved up one space underneath delete.
+- Colemak and Dvorak layers have been removed in this keymap as I do not and will not use them.
+
+
+#------------------------------------------------------
+
+#------------------------------------------------------
+
+#------------------------------------------------------
+
+#------------------------------------------------------
diff --git a/keyboards/preonic/keymaps/mechmaster48/rules.mk b/keyboards/preonic/keymaps/mechmaster48/rules.mk
new file mode 100644
index 00000000000..dcf16bef399
--- /dev/null
+++ b/keyboards/preonic/keymaps/mechmaster48/rules.mk
@@ -0,0 +1 @@
+SRC += muse.c