Here's a short story:

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). (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Question: What era does Adult contemporary cover?

The 1960s  and 1970s.