A frequently asked question is if hand hammered bowls can be tuned. However, the nature of hand hammering the bowls is not light or subtle, leaving the resulting note to be unpredictable. The thickness and diameter of a bowl can affect the pitch of the tones produced.
The following video is a spectrogram displaying the many separate frequencies produced by one singing bowl. The fundamental note and the overtone note are the most prominent notes, the fundamental note being the very bottom line, the overtone being the next above it. Suede or felt strikers are more likely to bring out the fundamental note whereas wood tools are more likely to bring out the overtone notes.
A tuner or spectrogram is used to denote the bowl.