How can two instruments play the same pitch but still sound different?

Two instruments can play the same fundamental pitch yet sound different due to a property called timbre, or tone color. While the fundamental frequency determines the perceived note, the unique quality of an instrument's sound is shaped by several physical factors:

• Overtone Structure: When an instrument produces a note, it also generates a series of overtones, or harmonics, which are frequencies that sound above the fundamental. The specific combination, relative intensity, and presence of these harmonics vary by instrument, creating a distinct "signature" sound.12
• Resonator Design: The size, shape, and material of an instrument's resonator—such as the body of a violin or the pipe of a wind instrument—determine which overtones are amplified or dampened.23
• Sound Envelope: Every instrument has a characteristic envelope, which describes the pattern of the sound's attack (how it begins), sustain (its steady state), and decay (how it fades).4
• Method of Excitation: How a sound is initiated—whether by bowing, plucking, or striking—significantly influences the resulting timbre by emphasizing different harmonic frequencies.35