Which of the following percussion notes would you obtain over the gastric bubble?

The appropriate percussion note over the gastric bubble is tympany. This sound is produced because the stomach, which contains gas and air, resonates when percussed. Tympany is characterized by a high-pitched, musical quality, which is distinct from other types of percussion sounds.

In the context of the gastric bubble, the presence of gas within the stomach creates the tympanic sound, while other types of percussion notes would not be present in this area. For instance, resonance typically occurs in areas with more solid structures, such as the lungs when filled with normal air, leading to a different sound quality.

Hyperresonance is a sound that may occur in situations where there is an abnormal amount of air, such as in cases of pneumothorax, and flatness is typically found over solid organs such as the liver. Therefore, it’s the tympanic note that reflects the characteristic air-filled content of the gastric bubble, making it the correct choice.