AEOLODION (also known as AEOLINE and AEOLODICON), one of several instruments of the harmonium type, invented and developed during the early part of the 19th century, having steel springs instead of the usual reeds. A closely similar instrument, employing wooden reeds instead of steel, was the aeolsklavier, and yet another was the aeolomelodicon or choraleon, in which the reeds were supplemented by brass tubes. The aeolopantalon in turn was in the nature of a combined harmonium and pianoforte designed so that either the one or the other could be used at will. None of these instruments succeeded in establishing itself.