WhistleJazz. The BGM of the late drinking genre is a whistle called "WhistleJazz". It is a light and cheerful music style with the whistle as the main instrument. This kind of music is often used in casual and relaxing situations, giving people a pleasant and relaxing feeling. WhistleJazz usually has a bright rhythm and smooth melody, and the whistle sound is crisp and pleasant, giving people a pleasant atmosphere.