When you mention a tuning fork, most people immediately think of a tuning fork used by piano tuners. These indicate the central A on a piano; the reference note used to get all the other notes in tune based on intervals. The central A is usually tuned to the 440 Hz frequency, although (slightly lower) exceptions are sometimes used for older music as this causes less vibrations per minute. Back in the day, a 432 Hz tuning was used more often since most people found it more pleasant. Old violins such as the iconic Stradivarius were originally tuned to 432 Hz, much like old Tibetan harmonic singing bowls. Even composers like Mozart and Verdi preferred this tuning. Today, tuning forks aren't only associated with the tuning of instruments. Special versions like Chakra tuning forks, often called planetary tuned forks, are actually tuned to natural or cosmic frequencies. The 432 Hz tuning fork is part of the same group of special tuning forks and is widely used in sound therapy and for meditation. The human body has its own unique frequency that can be thrown out of tune because of various factors. By using a special tuning fork, you can restore this natural frequency to help you feel better and experience an inner peace. Much like singing bowls and gongs, they're often used in therapy sessions.