Sela crystal singing bowls are suitable for making music as well as for meditation, yoga sessions and sound massages. Their soothing voice can help relieve stress, deeply relax and bring body and mind into harmony. The Crystal Singing Bowls can be played individually or in combination with other singing bowls or other instruments, such as the Sela Handpans. The 9" model is tuned to the note A with the internationally valid standard pitch of 440 Hertz (concert pitch A). This is the standard in the western music world, making it easy to combine with other instruments.