what bass note you use?

dont take this the worng way - but thats most be the most stupid question i ever heard on this site..

you use the one or ones that goes with the rest of your arrangement...

If your playing chords, pick one from a chord, usually the lowest one but not always the case. If its just a melody then pick the 1st or last note note from a melody or pick one thats on the down beat (i.e 4 by 4 kick)

white and black keys