Question about basslines and passing chords

[gtsjames]

This is a general theory question, lets say for instance that I have a song that moves between two basic chords, how can work with the the chords to get a bassline that doesnt sound too static or repetitive? The reason I am asking is that if I am the only musician then playing the same two chords for the whole song sounds very bland, boring and monotonous.
To go along with this When working those two chords, how do I determine what chords I can use as passing chords? Is that just up to me and what sound I like, or are there known patterns that I can use?
Preciate any info that anyone can share.

[4hisglory]

What two chords would you like to move between for example purposes?

[T-Block]

The only advice I can give from the question u have is to make sure when
u play the chords, have the right bass note that corresponds to those two chords then u can play whatever u want for the other bass notes.  Here is an example using C7 and F7 chords:

C / E-Bb-C
D, D#, E /
F / Eb-A-C
A, A#, B /
C / E-Bb-C
A#, G, F# /
F / Eb-A-C
D#, D, C# /
C / E-Bb-C
A#, G, D# /
F / Eb-A-C
F#, G, A# /
(repeat)

You get the idea?  The bass notes that u absolutely must play are C on the C7 chord and F on the F7 chord.  All other bass notes are fair game.  A bass line is whatever u want it to be.  Just start hitting random notes and see what u can come up with.  But, if u want to make it easier, follow some bass lines that have already been established like the blues scale or the basic shout pattern.

[playhear]

I’m not at my piano, so I can’t guarantee this is exactly what I do. Anyway, here’s a way to jazz up a 2-5-1 progression: Play ii-V-I7-I or some suitable variation, where I7 means the dominant seventh chord of the tonic. It is used as a passing chord here. I find the dominant seventh to be a suitable jazzy passing chord if played correctly.

Here’s an example written out in F:

LH / RH
G,D / F,A,Bb,D … Gmin9
C, G, Bb / E,A,Bb,D  …C13
F,C,Eb / Eb,G,A,D …F13
F,C,E / G,A,F …Fmaj9

Those are some pretty phat chords. Making sure to play the F13 as a passing chord. If this helps, I can discuss more…