History: What do we mean when we say, "electronic music"?

What do we mean when we say, "electronic music"?

• Any music produced or reproduced with electronic devices.
  While this is literally correctly, this answer misses the connotation.
• A process of combining two or more sounds to create a new sound.
  This is the definition to a different term.
• Music that uses electronic devices as a primary source.
  Perfect!
• Music created by combining and organizing sounds.
  This answer is too broad.