This Demonstration lets you test your ability to recognize the pitch of a note you are hearing. To practice, press the 14 small note buttons and try to guess which note you hear. Then, with the last wide button, you can test yourself (check the "randomize" button to begin). To hear the same random note again, uncheck the "randomize" box. To change the random note, check the "randomize" box. Each time you press this button, a new random note plays. Use the "instrument" popup menu to set which common instrument plays the notes. The length of the note can also be set with the "note length" slider.