Slap bass is a great tool to have in the box. I know there are times when I'll be playing a grooving song at church, something by Israel and New Breed or Fred Hammond, and the feeling will just hit me, "Slap that sucker!!!" So I give in to my artistic side of my brain and the end result is a happy congregation who was blessed by me giving the song just a little bit more groove.
Now the key here is to do it when it's needed or when it fits. Don't do it when it doesn't. You can't force groove. It has to flow. Knowing this comes with experience and trial and error so it's no wonder that you see many young bassists doing this in excess and more mature bassists doing it in moderation.
Now the key here is to do it when it's needed or when it fits. Don't do it when it doesn't. You can't force groove. It has to flow. Knowing this comes with experience and trial and error so it's no wonder that you see many young bassists doing this in excess and more mature bassists doing it in moderation.