The minor 7th chord has 4 notes: a root, a minor third, a fifth, and a minor 7th. Let's use G as an example. The G-minor 7th chord is going to be G (our root), B-flat (our minor third), D (our fifth), and F (our minor 7th). G, B-flat, D, and our lowered 7th, F. Here's the G-minor 7th chord in 2 octaves. And that's a minor 7th chord on the bass guitar.