The Reason Why All The Songs On The Radio Sound The Same Might Make You Blush

[eridani]

3. From Wikipedia

Sort of like the sounds of different instruments are more blurred together so you can't as easily distinguish them.

http://en.wikipedia.org/wiki/Timbre

In music, timbre (/ˈtæmbər/ TAM-bər or /ˈtɪmbər/ TIM-bər) also known as tone color or tone quality from psychoacoustics, is the quality of a musical note, sound, or tone that distinguishes different types of sound production, such as voices and musical instruments, string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the perception of timbre include spectrum and envelope.

In simple terms, timbre is what makes a particular musical sound different from another, even when they have the same pitch and loudness. For instance, it is the difference between a guitar and a piano playing the same note at the same loudness. Experienced musicians are able to distinguish between different instruments of the same type based on their varied timbres, even if those instruments are playing notes at the same pitch and loudness.