Klezmer is a Yiddish combination of two Hebrew words "Kley Zemer" which means: musical instruments.

The klezmer instruments were mainly acoustics, such as accordeon, clarinet, violin, stand bass and acoustic guitar.
 
Klezmer music was created by Jews in eastern Europe and it had the sound of mixed East European music and Jazz. 

Through the years, klezmer was neglected, but when European Jews  immigrated to America they revived klezmer music.

Now a days, klezmer is popular in the USA, Israel and Europe.