There are a lot of ways to play a one-octave scale on a bass guitar, but there's also a nice simple formula for beginners, so that you can get the sound in your ear and you can get the feel of the notes under your fingers. My formula is 2-4, 1-2-4, 1-3-4. So if we space our fingers, 1 per fret. And we pick a string low like the E-string, our lowest string. We can start with the second finger and play 2- 4. And then on the next string we play 1-2-4 and then on the next string we play 1-3- 4. And that's how you play a One-Octave Scale on a Bass Guitar.