1. Airflow: When the saxophonist blows air into the mouthpiece, they create an airstream that travels through the instrument.
2. Reed Vibration: The airstream strikes a thin piece of material called a "reed" located inside the mouthpiece. The reed vibrates rapidly as the air passes over it, generating sound waves.
3. Resonant Chamber: The vibrating reed sets the air inside the saxophone's body into sympathetic vibrations, amplifying the sound waves. The shape and design of the instrument, including the saxophone's tube, bell, and key mechanism, alter and amplify certain frequencies, shaping the overall tone.
4. Key Mechanism: By opening and closing the keys on the instrument, the saxophonist changes the length of the air column vibrating within the saxophone. Different key combinations change the pitch of the notes produced.
5. Embouchure: The manner in which the saxophonist shapes their mouth and lips around the mouthpiece affects the sound. By controlling their embouchure, the saxophonist can alter the timbre, pitch, and overall quality of the sound produced.
6. Resonance: The vibrations created by the reed resonate within the saxophone's body, which acts as an acoustic resonator. The shape of the saxophone and its materials (usually metal or wood) influence the sound's projection, clarity, and tonal color.
7. Feedback Loop: The sound waves continue to resonate inside the saxophone, reinforcing and sustaining the vibrations of the reed. This creates a feedback loop, maintaining the instrument's sound as long as the player continues to blow air through the mouthpiece.
In summary, the sound of an alto saxophone results from the vibration of the reed, which sets the air column in the saxophone's body into resonance, producing a rich and textured sound. The instrument's shape, key mechanism, and the player's technique all contribute to the distinct voice of the alto saxophone.