C major or A minor pentatonic scale notes would work ( same notes, different root); same applies to C major or A minor scale; or you could just target some of the chord tones.
I think your ears would tell you if something wasn't working, so try various options (you could even throw in a mass of notes that don't fit the scale in order to build tension before settling on the root note of whatever chord is being played at that point.
I wish this forum had a "block user" feature. Possibly I'm not the only one......