Adult contemporary music (AC) is a style of music, ranging from 1960s vocal and 1970s soft rock music to predominantly ballad-heavy music of the present day, with varying degrees of easy listening, pop, soul, rhythm and blues, quiet storm, and rock influence. Adult contemporary is rather a continuation of the easy listening and soft rock style that became popular in the 1960s and 1970s with some adjustments that reflect the evolution of pop/rock music. 

Adult contemporary tends to have lush, soothing and highly polished qualities where emphasis on melody and harmonies is accentuated. It is usually melodic enough to get a listener's attention, and is inoffensive and pleasurable enough to work well as background music. Like most of pop music, its songs tend to be written in a basic format employing a verse–chorus structure. 

Adult contemporary is heavy on romantic sentimental ballads which mostly use acoustic instruments (though bass guitar is usually used) such as acoustic guitars, pianos, saxophones, and sometimes an orchestral set. The electric guitars are normally faint and high-pitched. However, recent adult contemporary music may usually feature synthesizers (and other electronics, such as drum machines).
What does AC stand for?
What is that?
What does that style include?
What is it considered an extension of?
What changes have been made?
What is a quality that it has?
Is it loud and brash or soft and calming?
What is a good use for this style?
What is the format of it?
Are there more electric or acoustic sounds?
Adult contemporary
Adult contemporary
style of music
style of music
ranging from 1960s and 1970s soft rock to ballad-heavy music of today
ranging from 1960s vocal and 1970s soft rock music to predominantly ballad-heavy music of the present day
easy listening and soft rock style from the 1960s and 1970s
easy listening and soft rock style that became popular in the 1960s and 1970s
adjustments reflecting evolution of pop/rock music.
djustments that reflect the evolution of pop/rock music. 
Adult contemporary
Adult contemporary
It's lush and soothing
ush, soothing
background music
background music
verse–chorus structure
verse–chorus structure
acoustic
Adult contemporary is heavy on romantic sentimental ballads which mostly use acoustic instruments (though bass guitar is usually used) such as acoustic guitars, pianos, saxophones, and sometimes an orchestral set.