It is a high performance tuning fork program.It can generate 4 octave sound select by name.The movement of the octave : in a triangular sign. The movement of the semitone : with # and ?. The output selection of a continuous sound, continual sound, and the single sound can be done. (toggle)Concert Pitch – 440 Hz adjustableNo add.The sound of this program strongly depend on speaker of your device.(Specially in Low frequency)It is not because of me even if the sound is bad.