Here is how you play the note "C" on the bass guitar. So if our third string open is "A"; which is the string seconds closest to you, we are going to skip one fret to get to "B", and then there is no skip between "B" and "C". So the third fret on the A string is going to be "C". We can also find "C", the same "C", by going to our E string; the forth string, the string that is closest to you, and going to the eighth fret. We can also find a "C" by going to our highest string; the G string, by doing the same thing. If we that this is G, we will skip a note to get to "A" (second fret of G string) then skip a note to get to "B" (forth fret of the G string), and then there is no skip to get to our "C" (fifth fret of G string). So the fifth fret of our G string is a "C". That same "C" can be found at the tenth fret on the D string. And then again at the fifteenth fret on the A string. And that is how you play the note C on the bass guitar.