Abstract: Apparatus for adjusting the tuning of a musical instrument to cause the instrument to sound in just intonation while the instrument is being played comprises a data base in memory for storing an array of just intonation tone identifiers. The tone identifiers in the array are arranged by key, chordal root and tone according to just intonation relationships defined by the ratios of a scale selected by the musician. A selector unit is provided for enabling a musician to select a key and/or a chordal root, as a result of which a CPU retrieves from the array a set of tone identifiers in just intonation corresponding to the selected key or chordal root and transmits them to the sounding means of the instrument.

Abstract: A compound bow has a body having a pair of ends each carrying a respective limb and with a bolt extending between each limb and the respective body end is provided with a draw-weight gauge for each limb. Each gauge has a gear head on the respective bolt. A holder adjacent the respective bolt rotatably supports a threaded rod extending along an axis generally perpendicular to the respective bolt. A gear on the rod is in constant mesh with the gear head on the respective bolt. A scale is fixed on the bow along the rod and an indicator threaded onto the rod can be displaced thereby along the scale.