Final answer:
Musical sounds differ based on loudness, quality (timbre), and pitch. Loudness relates to sound's intensity, pitch to the frequency, and timbre gives the character distinguishing different instruments even at the same pitch and loudness.
Step-by-step explanation:
Musical sounds differ from one another in loudness, quality (also known as timbre), and pitch. Loudness refers to the perception of a sound's intensity, and it can vary based on the amplitude of the sound waves. However, loudness also depends on the frequency since the human ear has differing sensitivity levels across the hearing frequency range. Pitch is the perception of a sound's frequency, which allows us to distinguish between higher and lower notes. Timbre is the aspect that enables the differentiation of two sounds having the same pitch and loudness; it's the character or quality of a musical sound or voice as distinct from its pitch and intensity. Timbre arises from a complex interplay of frequency, amplitude, and the timing of sound waves, and it's influenced by the resonances of the particular instrument producing the sound. An instrument like a violin thus produces a sound with a different timbre from a piano, even when they are playing the same note at the same loudness.