Music

This is the music module and you can use it to create and play melodies. By default sound output will be via the edge connector on pin 0 and the built-in speaker V2. You can connect wired headphones or a speaker to pin 0 and GND on the edge connector to hear the sound:

_images/music-pins.png

You can also disable/enable the built-in speaker or output sound on another pin.

To access this module you need to:

import music

We assume you have done this for the examples below.

Musical Notation

An individual note is specified thus:

NOTE[octave][:duration]

For example, A1:4 refers to the note “A” in octave 1 that lasts for four ticks (a tick is an arbitrary length of time defined by a tempo setting function - see below). If the note name R is used then it is treated as a rest (silence).

Accidentals (flats and sharps) are denoted by the b (flat - a lower case b) and # (sharp - a hash symbol). For example, Ab is A-flat and C# is C-sharp.

Note names are case-insensitive.

The octave and duration parameters are states that carry over to subsequent notes until re-specified. The default states are octave = 4 (containing middle C) and duration = 4 (a crotchet, given the default tempo settings - see below).

For example, if 4 ticks is a crotchet, the following list is crotchet, quaver, quaver, crotchet based arpeggio:

['c1:4', 'e:2', 'g', 'c2:4']

The opening of Beethoven’s 5th Symphony would be encoded thus:

['r4:2', 'g', 'g', 'g', 'eb:8', 'r:2', 'f', 'f', 'f', 'd:8']

The definition and scope of an octave conforms to the table listed on this page about scientific pitch notation. For example, middle “C” is 'c4' and concert “A” (440) is 'a4'. Octaves start on the note “C”.

Functions

music.set_tempo(ticks=4, bpm=120)

Sets the approximate tempo for playback.

A number of ticks (expressed as an integer) constitute a beat. Each beat is to be played at a certain frequency per minute (expressed as the more familiar BPM - beats per minute - also as an integer).

Suggested default values allow the following useful behaviour:

  • music.set_tempo() - reset the tempo to default of ticks = 4, bpm = 120
  • music.set_tempo(ticks=8) - change the “definition” of a beat
  • music.set_tempo(bpm=180) - just change the tempo

To work out the length of a tick in milliseconds is very simple arithmetic: 60000/bpm/ticks_per_beat . For the default values that’s 60000/120/4 = 125 milliseconds or 1 beat = 500 milliseconds.

music.get_tempo()

Gets the current tempo as a tuple of integers: (ticks, bpm).

music.play(music, pin=pin0, wait=True, loop=False)

Plays music containing the musical DSL defined above.

If music is a string it is expected to be a single note such as, 'c1:4'.

If music is specified as a list of notes (as defined in the section on the musical DSL, above) then they are played one after the other to perform a melody.

In both cases, the duration and octave values are reset to their defaults before the music (whatever it may be) is played.

An optional argument to specify the output pin can be used to override the default of microbit.pin0. If we do not want any sound to play we can use pin=None.

If wait is set to True, this function is blocking.

If loop is set to True, the tune repeats until stop is called (see below) or the blocking call is interrupted.

music.pitch(frequency, duration=-1, pin=pin0, wait=True)

Plays a pitch at the integer frequency given for the specified number of milliseconds. For example, if the frequency is set to 440 and the length to 1000 then we hear a standard concert A for one second.

Note that you can only play one pitch on one pin at any one time.

An optional argument to specify the output pin can be used to override the default of microbit.pin0. If we do not want any sound to play out of the pins we can use pin=None.

If wait is set to True, this function is blocking.

If duration is negative the pitch is played continuously until either the blocking call is interrupted or, in the case of a background call, a new frequency is set or stop is called (see below).

music.stop(pin=pin0)

Stops all music playback on the built-in speaker and any pin outputting sound. An optional argument can be provided to specify a pin, eg. music.stop(pin1).

music.reset()

Resets the state of the following attributes in the following way:

  • ticks = 4
  • bpm = 120
  • duration = 4
  • octave = 4

Built in Melodies

For the purposes of education and entertainment, the module contains several example tunes that are expressed as Python lists. They can be used like this:

>>> import music
>>> music.play(music.NYAN)

All the tunes are either out of copyright, composed by Nicholas H.Tollervey and released to the public domain or have an unknown composer and are covered by a fair (educational) use provision.

They are:

  • DADADADUM - the opening to Beethoven’s 5th Symphony in C minor.
  • ENTERTAINER - the opening fragment of Scott Joplin’s Ragtime classic “The Entertainer”.
  • PRELUDE - the opening of the first Prelude in C Major of J.S.Bach’s 48 Preludes and Fugues.
  • ODE - the “Ode to Joy” theme from Beethoven’s 9th Symphony in D minor.
  • NYAN - the Nyan Cat theme (http://www.nyan.cat/). The composer is unknown. This is fair use for educational porpoises (as they say in New York).
  • RINGTONE - something that sounds like a mobile phone ringtone. To be used to indicate an incoming message.
  • FUNK - a funky bass line for secret agents and criminal masterminds.
  • BLUES - a boogie-woogie 12-bar blues walking bass.
  • BIRTHDAY - “Happy Birthday to You…” for copyright status see: http://www.bbc.co.uk/news/world-us-canada-34332853
  • WEDDING - the bridal chorus from Wagner’s opera “Lohengrin”.
  • FUNERAL - the “funeral march” otherwise known as Frédéric Chopin’s Piano Sonata No. 2 in B♭ minor, Op. 35.
  • PUNCHLINE - a fun fragment that signifies a joke has been made.
  • PYTHON - John Philip Sousa’s march “Liberty Bell” aka, the theme for “Monty Python’s Flying Circus” (after which the Python programming language is named).
  • BADDY - silent movie era entrance of a baddy.
  • CHASE - silent movie era chase scene.
  • BA_DING - a short signal to indicate something has happened.
  • WAWAWAWAA - a very sad trombone.
  • JUMP_UP - for use in a game, indicating upward movement.
  • JUMP_DOWN - for use in a game, indicating downward movement.
  • POWER_UP - a fanfare to indicate an achievement unlocked.
  • POWER_DOWN - a sad fanfare to indicate an achievement lost.

Example

"""
    music.py
    ~~~~~~~~

    Plays a simple tune using the Micropython music module.
    This example requires a speaker/buzzer/headphones connected to P0 and GND,
    or the latest micro:bit device with built-in speaker.
"""
from microbit import *
import music

# play Prelude in C.
notes = [
    'c4:1', 'e', 'g', 'c5', 'e5', 'g4', 'c5', 'e5', 'c4', 'e', 'g', 'c5', 'e5', 'g4', 'c5', 'e5',
    'c4', 'd', 'a', 'd5', 'f5', 'a4', 'd5', 'f5', 'c4', 'd', 'a', 'd5', 'f5', 'a4', 'd5', 'f5',
    'b3', 'd4', 'g', 'd5', 'f5', 'g4', 'd5', 'f5', 'b3', 'd4', 'g', 'd5', 'f5', 'g4', 'd5', 'f5',
    'c4', 'e', 'g', 'c5', 'e5', 'g4', 'c5', 'e5', 'c4', 'e', 'g', 'c5', 'e5', 'g4', 'c5', 'e5',
    'c4', 'e', 'a', 'e5', 'a5', 'a4', 'e5', 'a5', 'c4', 'e', 'a', 'e5', 'a5', 'a4', 'e5', 'a5',
    'c4', 'd', 'f#', 'a', 'd5', 'f#4', 'a', 'd5', 'c4', 'd', 'f#', 'a', 'd5', 'f#4', 'a', 'd5',
    'b3', 'd4', 'g', 'd5', 'g5', 'g4', 'd5', 'g5', 'b3', 'd4', 'g', 'd5', 'g5', 'g4', 'd5', 'g5',
    'b3', 'c4', 'e', 'g', 'c5', 'e4', 'g', 'c5', 'b3', 'c4', 'e', 'g', 'c5', 'e4', 'g', 'c5',
    'a3', 'c4', 'e', 'g', 'c5', 'e4', 'g', 'c5', 'a3', 'c4', 'e', 'g', 'c5', 'e4', 'g', 'c5',
    'd3', 'a', 'd4', 'f#', 'c5', 'd4', 'f#', 'c5', 'd3', 'a', 'd4', 'f#', 'c5', 'd4', 'f#', 'c5',
    'g3', 'b', 'd4', 'g', 'b', 'd', 'g', 'b', 'g3', 'b3', 'd4', 'g', 'b', 'd', 'g', 'b'
]

music.play(notes)