It is sometimes surprising to hear the way that some style’s bass lines are different than what you might expect when just listening to the drum groove. For example: in Country music the Train Beat is really busy – suggesting the movement of a train on the tracks. While the drummer plays the characteristically a floor bass drum and the consistent snare pattern emphasizing the upbeats the bassist often plays half notes with the occasional two quarter notes at the end of the two bar phrase. If you took the bass line by itself it sounds like nothing special but when you hear it against the drums it makes total sense. Knowing what the appropriate groove is the key here.
If you look at the following examples, even if you don’t read music, you can see how the two parts correspond with each other. < br/>
Here is the drum groove:
and here is the bass line:
It is often the case that when the drummer gets busy, the bassist simplifies his lines. You find that in everything from Afro-cuban and Drum & Bass to Country and Blues. Two exceptions are Techno, where the bass is really emulating samples or a synthesizer bass line and Metal where the entire band often plays huge amounts of notes simultaneously.
Once you and your drummer know the authentic parts the rest of the band will probably be able to figure it out. It is also easy to change the bass line to match your personal style once you see and example of what groove sounds like. The book also details chord progressions, tone choices, and other info that will help you sound like you have played these grooves a thousand times.