Simplify the following text for a Grade 10 native English-speaking person.
Original: The acoustic guitar group also includes unamplified guitars designed to play in different registers , such as the acoustic bass guitar , which has a similar tuning to that of the electric bass guitar .
Simplified: The term acoustic guitar is generally used for a guitar used for popular music , even though a classical guitar is also an acoustic instrument . There are many other different types of acoustic guitars from different parts of the world .