A singer's vocal range is determined by their physical makeup, training, and musical style. Physical makeup, including vocal cord length, thickness, and flexibility, plays a significant role in determining a singer's range. Training, such as vocal exercises, warm-ups, and practice, helps singers control and strengthen their vocal muscles, improve breath support, and develop proper resonance. The musical style also influences the range a singer needs to possess and develop, with classical music requiring a wider range, while pop or rock music may focus on a specific range. It is important to note that the microphone a singer uses does not directly affect their vocal range, as they capture and reproduce the sound accurately, regardless of the singer's range. In conclusion, a singer's vocal range is determined by their physical makeup, training, and the demands of their musical style.