a great exercise in polytonality for bassists is to play two harmonics on the g and d strings at a few different places.
let's start w harmonics at the 5th fret which yields those same two pitches...G and D.
then, as they ring out... you play a fretted bass note under them on the A or E string. then play "name that chord".
a few that i like:
playing an Eb on the A string = Ebmaj7
w an F on the A strng= Fadd9 add13
then play some of the other two note harmonics on the G and D strings (4th fret, 7th fret) and play bass notes against those and name the chord. hours of good clean fun!
