The best replacement for harmonica is harp.

The best alternatives to harmonica are rated as following:
★★★★★  harp
★★★★  guitar
★★★  mouth organ
★★  harmonica
★★  melodica
★★  ocarina
★★  man with no name
★  saxophone
★  blues harp
★  recorder
★  chromatic
★  diatonic
  flute
  an harmonica
  armonica
  diatonic harmonica
  kazoo

Your alternative for harmonica is not listed? Suggest!
Speaking about harmonica, one probably shouldn't forget about bending.

Other search terms related to harmonica and their ratings are:
★★★★★ bending
You have in mind a companion for harmonica and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of harmonica in all years. Click on graph for more.
harmonica
harp
guitar