If you learn a handful of music theory (arpeggios/chord tones, some scales, and modes) you have all the information you'd ever need to create hundreds of bass lines.
These same ideas crop up time and time again in all kinds of different styles.
Provided you use some tasteful rhythms and soulful techniques, you'll have yourself a bass line!
Learn how in this video lesson.
Scroll down for the backing track and PDF downloads and make sure to check out some of my other related lessons.
The lightbulb moments will soon hit you!
Bass Guitar Backing Track
Bass Guitar Scale Shapes And Patterns
These lessons may be worth a little of your time as they will shine more light on what you need to know. Don't worry, it seems complex at the beginning but it really isn't (once you know how you'll find it easy!).