Help with melodic basslines?

Support, Help & Resources
1

Hi! I’m new to this, I’m starting to program music with Sonic Pi, and I’m having a lot of fun! I have a few questions, if anyone here knows the software, I need some help with something.

I’m trying to create a bassline that follows the note of the chord that’s currently playing. I’d like to do this without having to write each note individually. I know there has to be a much simpler way.

I’ve attached a screenshot so you can see how the code is written for now.

I initially thought I could do it with “if” statements, but I couldn’t find a way to program it correctly. Any ideas? Thanks!

image
image953×427 11.7 KB

2

Hi

Welcome to Sonic Pi! Because a chord is a ring array, we can target individual chord tones by index (to derive a bassline from a given chord); 0 = root, 1 = 3rd, 2 = 5th etc:

live_loop :tonic do
  play chord(:e, :minor)[0], release: 0.1
  sleep 0.5
end

HTH

PD-Pi

3

[EDIT]

You can get the bassline to follow the chord progression like this (apologies if a bit clunky, haven’t used Sonic Pi in a while):

triads = [":e3",":a3","b3",":e3"].ring

use_synth :fm
live_loop :chord do
  tick
  play chord(triads.look, :minor)+12
  sleep 2
end

use_synth :bass_foundation
use_synth_defaults pitch: -12
live_loop :root do
  tick
  note = chord(triads.look, :minor)[0]
  4.times do
    play note, release: 0.6
    sleep 0.5
  end
end

PD-Pi

1 Like
4

Okay! That works, thank you so much! I’ve been very busy these past few days and haven’t had time to reply quickly. I have a few questions about what you wrote.

Why do you put a “tick” command before each “play”? What does it do?

Does putting “.ring” at the end of the square brackets turn the content into a ring? Is it the same as using “(ring)”?

5

Hi

tick is a thread/loop-independent counter, which reads through the ring array of named chords called ‘triads’ via .look. This generates a chord sequence (the second loop simply targets the root note of each chord, see: Help/Lang/tick). Without the tick, each loop would only target the first element in that ring array. And yes, .ring is exactly the same as (ring).

PD-Pi

6

Just to clarify, I think what Brendan means here by ‘thread/loop-independent’ is ‘isolated per-thread/loop’, rather than ‘isolated from any thread/loop’.
(I think the word Sam often used was ‘Thread-local’ (i.e. local to the thread/loop).

1 Like
7

Thanks for refining my clumsy syntax :wink:

8

Also, remember that notes are just numbers, and you can do math. If you want the note to be 2 octaves below the first note of the chord, just do

live_loop :tonic do
  play chord(:e, :minor)[0] - 24, release: 0.1
  sleep 0.5
end

Have fun exploring sonic pi! It’s a blast!