Acoustic instruments

Acoustic music is music that solely or primarily uses instruments that produce sound through acoustic means, as opposed to electric or electronic means. The retronym "acoustic music" appeared after the advent of electric instruments, such as the electric guitar, electric violin, electric organ and synthesizer.

It has its origins in the folk music of the 1960s. Following the increasing popularity of the television show MTV Unplugged during the 1990s, acoustic (though in most cases still electrically amplified) performances by musicians (most notably grunge bands) who usually rely on electronic instruments became colloquially referred to as "unplugged" performances. The trend has also been dubbed as "acoustic rock" in some cases.

Writing for Splendid, music reviewer Craig Conley suggests, "When music is labeled acoustic, unplugged, or unwired, the assumption seems to be that other types of music are cluttered by technology and overproduction and therefore aren't as pure".

...
Wikipedia