Frequency and energy are related through quantum mechanics, but this relationship is not straightforward in classical physics. As energy increases, frequency typically increases, but exceptions exist, such as low-energy, high-frequency waves. In the context of a wine glass, filling it with liquid decreases the frequency of the sound produced because the water requires more energy to move, thus lowering the wave's energy. The frequency of a wine glass can also be affected by its effective vibrating area, which is reduced when water is added, leading to higher frequencies. Overall, the relationship between frequency and energy can vary depending on the physical context and medium involved.