Two acoustic instruments were built to assist in explorations of unfamiliar tunings. The Columbine (1977), a metallophone using a 23-pitch-per-octave tuning, and the Amaranth (1981), a 24-stringed instrument with moveable bridges, have been used in composing and performing music for unorthodox tunings. The development of playing techniques specific to the two instruments and the musical implications and uses of the tunings are outlined.