ncgs part 2 making a bass line

part2-ncgs-bass.rb

##| part2-ncgs-bass.rb
##| The bass will set the rhythm and get
##| folks nodding their heads

##| make sure your tempo is the same as
##| whatever you chose for your drums

use_bpm 60


##| 1) Playing notes
##| There is another way to play sounds with
##| Sonic Pi: the play command.
##| Play around with the command and see if
##| you can figure out how it works.
##| -----------------------------------------

play 60

##| 2) Choosing sounds
##| Sonic Pi comes with different synthesizers
##| These synths generate tones that sound VERY
##| different. Explore some of the different
##| synth sounds by moving the folling line of
##| code to line 9
##| -----------------------------------------

use_synth :beep #beep is the default

##| 3) Note Length
##| We can use the sleep command that we used
##| in the drum section to create different
##| note durations. We are using a convention
##| 1 beat = 1 quarter note.
##| So if we 'sleep 1' then we are playing a quarter
##| Sleeping for half of a beat or, sleep 0.5, is
##| sleeping for half of a quarter note. This would be an
##| eigth note. Half of that, sleep 0.25, would a sixteenth note
##| and so on
##| -----------------------------------------

comment do
  play 57
  sleep 1
  play 59
  sleep 0.5
  play 60
  sleep 0.125
  play 60
  sleep 0.125
  play 60
  sleep 0.125
  play 60
  sleep 0.125
  play 67
  sleep 0.5
  play 64
  sleep 0.5
  play 60
  sleep 1
end


##| 4) Building a Bass Line
##| Now we are going to put some notes together to create a simple bass line
##| For the bass line we need notes and a duration to play the notes
##| to make it easier to groove I am going to introduce some concepts
##| that will make it much easier for you to experiment with ideas
##| -----------------------------------------

##| Notes:
##| Let's make a list of the notes that we want to play. Then we will use
##| Sonic Pi's metronome to step through the list and play the corresponding
##| note at that position in the list. Below is the list from the example above:

bass_line = ring 57, 59, 60, 60, 60, 60, 67, 64, 60

##| Easy. It's just the numbers that we used separated by a comma
##| Now do the same things for the durations
durations = ring 1, 0.5, 0.125, 0.125, 0.125, 0.125, 0.5, 0.5, 1

##| Question: Can you guess the total duration? Were you right? What is the total? Can you
##| explain why?


##| Before moving on, let's make another change. Let's use short hand note names
##| instead of those numbers. Remember 1 = quarter note, 0.5 = eight, etc. Here is the
##| shorthand that we will use:
##|   qt = quarter
##|   et = eight
##|   st = sixteenth
##|   ts = thirty-second
##| Substituting our code into the durations the list now reads:
qt = 1
et = 0.5
st = 0.25
ts = 0.125
durations = ring qt, et, ts, ts, ts, ts, et, et, qt

##| You can think of this as we are telling the bass player, 'Play a
##| quarter note, an eight note, then rattle off 4 32nds, and then bring
##| it on home with a couple of eights and a quarter...ya dig?'

##| Great. Now how do we use this? Run the following code and I will step through it
##| during the workshop. You can also look up the commands in the help by clicking on the
##| term and then pressing [control + i]. If you do that then you will see the term and its
##| definition appear in the window below the Buffer.

uncomment do
  live_loop :bass_line do
    # make the metronome tick once;
    # use its value to find the note in the bass_line
    play bass_line[ tick ]
    
    # LOOK at the metronome value and use its value
    # use its value to find the duration to sleep in the durations list
    sleep durations[ look ]
  end
end


##| 4) Compose a bass line
##| Use your chosen synth, notes, and sleep patterns
##| to create a bass line.
##| For starters try to keep the bass line to
##| 4 bars (total of sleep time = ??)
##| -----------------------------------------