A C program that plays a specified note on a macOS device's built-in hardware, using AudioToolbox. The user may give the program a frequency to play, and set the octave and volume to play it at.

• A Mac system with macOS 10.0+

clang -lc -framework AudioToolbox NotePlayer.c -o NotePlayer

./NotePlayer <frequency> <octave difference> <up(0)/down(1)> <optional: volume(1-100)>

Ex for one octave above middle C:

./NotePlayer 261.6 1 0

Kevin Schulcz