Playing the Arpeggios
A great first step to getting comfortable with a chord progression is to play the arpeggios. This will get your fingers used to the shapes, and your ears used to the sound.
Play the arpeggios to each of the four chords, one bar each. Here are the four triads for the I-V-vi-IV progression. See the exercises for playing them to a metronome.
Creating Your Own Bassline
Once you are comfortable with the arpeggios, you can start to improvise with the notes of each chord and see what you can create.
What can you do? Try this to start:
- Change the rhythms.
- Change the order of the notes.
- Leave some notes out.
- Repeat notes.
What else can you imagine?
Remember, a good bassline has two key ingredients: (1) rhythm, and (2) it defines the chords. If you are sticking to the chord tones for each chord, you're defining the chord.
Where you might get into trouble is when your rhythm is inconsistent. Maybe you speed up or slow down the tempo. Play with a metronome, a drum beat, or a play-along track. Try recording yourself, or play for others and get an honest opinion.
If you are really lost, start with playing the root of each chord on the first beat of each chord change. Although it's not a rule, that's what happens most of the time. This can act as the skeleton for your bassline.
Once you're comfortable with the roots, keep them going and experiment with inserting a few of the other notes of each chord in between.
You're going to have to do this a lot to get better at it. As you absorb the sounds and your fingers find their way, I promise it will get better.
I-V-vi-IV Bass Exercises
In the exercises, I've included some examples to show you what you might be able to create as well as a play-along track in the key of G.
On your own, try playing this in different keys. Try improvising over some of the many songs which use this progression. Learn some other bassist's basslines on this progression. You will surely run into some notes we haven't yet discussed. For now, pay attention to the diatonic chord tones.