accordion vs harmonica

accordion

noun
  • A box-shaped musical instrument with means of keys and buttons, whose tones are generated by play of the wind from a squeezed bellows upon free metallic reeds. 

  • A set of items (concepts, links, or otherwise) that can be packed and unpacked cognitively, or their representation as a set of virtual objects. 

  • A vertical list of items that can be individually expanded and collapsed to reveal their contents. 

verb
  • To fold up, in the manner of an accordion 

harmonica

noun
  • A musical wind instrument with a series of holes for the player to blow into, each hole producing a different note 

  • A musical instrument, consisting of a series of hemispherical glasses which, by touching the edges with the dampened finger, give forth the tones. 

  • A toy instrument of strips of glass or metal hung on two tapes, and struck with hammers. 

How often have the words accordion and harmonica occurred in a corpus of books? (source: Google Ngram Viewer )