Music sequencer for the BBC micro:bit

music_sequencer.py

# MUSIC SEQUENCER by Darryl Sloan (30/11/2017)

# Step 1: press A to toggle the first note of the desired scale, then B to select.
# Step 2: press A to toggle the time signature (3/4, 4/4 or 5/4), then B to select.
# Step 3: press A to toggle the desired number of patterns (1 to 4), then B to select.
# Press A to move the range of notes selected. Press B to randomise the selected notes.
# The direction of tilt determines which scale the random notes conform to:
# Left = minor; right = major; forward = minor pentatonic; backward = major pentatonic.
# While holding A during the first note of the sequence, tilting up/down increases/decreases the tempo,
# tilting left/right selects a lower/higher octave.
# While holding A, tap B to show the notes in English for transcription purposes.

from microbit import *
import music
import random

octave = 3
tempo_adjust = 90
music.set_tempo(bpm = tempo_adjust)
selection = 0
pattern = 0
all_notes = ("C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B")
major = (0, 2, 4, 5, 7, 9, 11)
minor = (0, 2, 3, 5, 7, 8, 10)
major_pent = (0, 2, 4, 7, 9)
minor_pent = (0, 3, 5, 7, 10)
scale_major = ["", "", "", "", "", "", ""]
scale_minor = ["", "", "", "", "", "", ""]
scale_major_pent = ["", "", "", "", ""]
scale_minor_pent = ["", "", "", "", ""]

# User selects scale
scale = 0
display.scroll("Scale")
while True:
    display.show(all_notes[scale])
    if button_a.was_pressed():
        scale += 1
        if scale == 12:
            scale = 0
    if button_b.was_pressed():
        break
for i in range(7):
    scale_major[i] = all_notes[major[i]]
    scale_minor[i] = all_notes[minor[i]]
for i in range(5):
    scale_major_pent[i] = all_notes[major_pent[i]]
    scale_minor_pent[i] = all_notes[minor_pent[i]]
notes = scale_major
    
# User selects time signature
beat = 4
display.scroll("Beat")
while True:
    display.show(str(beat))
    if button_a.was_pressed():
        beat += 1
        if beat == 6:
            beat = 3
    riff_length = beat*4
    if button_b.was_pressed():
        break

# User selects quantity of patterns
patterns = 1
display.scroll("Patterns")
while True:
    display.show(str(patterns))
    if button_a.was_pressed():
        patterns += 1
        if patterns == 5:
            patterns = 1
    if button_b.was_pressed():
        break

# Load example riff
sequence = []
default = [all_notes[scale]+"4"]
for i in range(beat-1):
    default += [all_notes[scale]+"3"]
for i in range(patterns*4):
    sequence += default

while True:
    x, y = 0, 0
    for i in range(riff_length):

        # Refresh display
        display.clear()
        display.set_pixel(pattern, 4, 9)
        for highlight in range(beat):
            display.set_pixel(highlight, selection, 5)
        display.set_pixel(x, y, 9)

        # User reveals notes in English
        if button_a.is_pressed() and button_b.was_pressed():
            for p in range(patterns):
                text = ""
                for q in range(8):
                    display.show(str(p+1))
                    sleep(200)
                    display.clear()
                    sleep(200)
                for j in range(riff_length):
                    text += sequence[j+(pattern*riff_length)]+"  "
                display.scroll(text)

        # User adjusts octave or tempo
        if i == 0 and button_a.is_pressed():
            if accelerometer.get_x() < 0 and abs(accelerometer.get_y()) < abs(accelerometer.get_x()) and octave > 1:
                octave -= 1
            if accelerometer.get_x() > 0 and abs(accelerometer.get_y()) < abs(accelerometer.get_x()) and octave < 6:
                octave += 1
            if accelerometer.get_y() < 0 and abs(accelerometer.get_x()) < abs(accelerometer.get_y()) and tempo_adjust < 200:
                tempo_adjust += 10
            if accelerometer.get_y() > 0 and abs(accelerometer.get_x()) < abs(accelerometer.get_y()) and tempo_adjust > 60:
                tempo_adjust -= 10
            music.set_tempo(bpm = tempo_adjust)

        # User changes current selection
        if button_a.was_pressed():
            selection += 1
        if selection == 4:
            selection = 0

        # User randomises selected notes
        if button_b.was_pressed():
            if accelerometer.get_x() < 0 and abs(accelerometer.get_y()) < abs(accelerometer.get_x()):
                notes = scale_minor
            if accelerometer.get_x() > 0 and abs(accelerometer.get_y()) < abs(accelerometer.get_x()):
                notes = scale_major
            if accelerometer.get_y() < 0 and abs(accelerometer.get_x()) < abs(accelerometer.get_y()):
                notes = scale_minor_pent
            if accelerometer.get_y() > 0 and abs(accelerometer.get_x()) < abs(accelerometer.get_y()):
                notes = scale_major_pent
            for r in range(selection*beat, selection*beat+beat):
                sequence[r+(pattern*riff_length)] = random.choice(notes)+str(random.randint(octave, octave+1))

        # Play current note
        music.play(sequence[i+(pattern*riff_length)]+":1")

        # Move playhead forward by 1
        x += 1
        if x == beat:
            x = 0
            y += 1
        if y == 4:
            y = 0

        # Move pattern forward by 1
        if x == 0 and y == 0:
            pattern += 1
            if pattern == patterns:
                pattern = 0

This is so awesome, I can't believe how complete this program is for something that fits on a Micro:Bit! I'm going to have so much fun playing with this, thank you :)