The term "busy bass" can be used to describe both upright bass and electric bass playing. In upright bass playing, busy bass lines are often created by using a variety of techniques, including pizzicato, arco, and slapping. In electric bass playing, busy bass lines are often created using a combination of fingerstyle picking, tapping, and slapping.
Busy bass lines can be challenging to play, but they can also be very rewarding. They can add a great deal of interest and excitement to a musical performance, and they can help to create a strong foundation for the rest of the band.
Some examples of famous bass players who are known for their busy bass lines include Jaco Pastorius, Larry Graham, and Flea.