# Lesson 7

# Rhythm Lesson - Part 2. In this lesson, we
# will use variables and percussion sounds
# to program rhythm patterns, and meters with
# a "metronome."

# General Instructions:
#
# This lesson contains three examples and
# three exercises (A, B, C).
#
# To listen to an example, change "comment"
# to "uncomment" on the "comment do" line,
# then click the "Run" menu command at the
# top of the Sonic Pi editor window.
# When you are done with the example, turn
# it off by changing "uncomment" back to
# "comment," and move on to the next section
# of the lesson.
#

# Note Values. We can use variables to assign
# numbers and fractions to beat values to make
# our rhythm code easier to read and understand.

# Example 1: Some standard rhythm note values:

comment do
  whole = 1
  half_dot = 0.75
  half = 0.5
  quarter_dot = 0.375
  quarter = 0.25
  eighth = 0.125
  sixteenth = 0.0625
  play :C5
  sleep half
  play :E5
  sleep quarter
  play :G5
  sleep quarter
  play :B4
  sleep quarter_dot
  play :C5
  sleep sixteenth
  play :D5
  sleep sixteenth
  play :C5
end

# Exercise A: Add the following rhythm-value
# variables with appropriate value assignments
# to Example 1:
#   1) eighth_dot
#   2) triplet 8th (1/3 of a quarter note)
#   3) triplet quarter (1/3 of a half note)

# Example 2: Creating Pie Rhythms. In this
# example, a Pie is a half note, Apple is
# two quarter notes, etc.

comment do
  use_bpm 45
  half = 0.5
  quarter = 0.25
  eighth = 0.125

  # Pie
  play :C
  play :G
  sleep half

  # Apple
  2.times do
    play :C
    play :G
    sleep quarter
  end

  # Pie
  play :C
  play :G
  sleep half

  # Blackberry
  play :C
  play :G
  sleep quarter
  2.times do
    play :C
    play :G
    sleep eighth
  end

  #Huckleberry
  4.times do
    play :C
    play :G
    sleep eighth
  end

  # Apple
  2.times do
    play :C
    play :G
    sleep quarter
  end

  # Pie
  play :C
  play :G
  sleep half

end

# Exercise B
# Change the beat values / names in Example 2:
#   1) Pie is a quarter note.
#   2) Apple is two 8th notes.
#   3) Huckleberry is four 16th notes.
#   4) Blackberry is an 8th note followed by
#      two 16th notes.
#   5) Create a Butterscotch rhythm (two 16th
#      notes followed by an 8th note) to
#      replace the last Apple rhythm.

# Example 3: Metronome. Note: the "loop" command
# causes the following block of code to repeat
# "forever." Click "Stop" at the top of the
# Sonic Pi editor to break the loop.

comment do
  use_bpm 120

  # This example represents 4/4 meter
  loop do
    sample :drum_heavy_kick
    sleep 1
    sample :perc_snap
    sleep 1
    sample :bd_fat
    sleep 1
    sample :perc_snap
    sleep 1
  end
end

# Exercise C
# Change Example 3:
#   1) experiment with different bpms
#   2) Change the loop so that it plays different
#      metrical patterns (experiment with different
#      drum or percussion sounds)
#     a) 3/4 (one strong beat)
#     b) 5/4 (2 + 3)
#     c) 5/4 (3 + 2)
#     d) 7/8