The Importance of Frequency in Music and Sound

by jtalwar

Do you ever wonder how you can distinguish one voice from another?  What is it that allows you to distinguish one note from another in a musical composition?  The answer is frequency, which can be defined as the number of repeating events per unit time.  Simply put, frequency is the rate of sound vibration.

Outside of our ability to hear and distinguish specific sounds, you may be wondering why frequency is so important in music.  Each instrument has a range of frequencies it can play and correspondingly each note on a particular instrument has a different frequency.  Would you ever confuse middle C on a guitar with middle C on a piano?  Hopefully the answer is no.  Your ears are sensitive enough to distinguish the slightest differences in frequencies.

Building on this an important question comes to mind.  If you isolated the works of particular composers and evaluated the frequency spectrum of the musical signal (such as through a Fourier transform), would you find any frequency components that would dominate.  Can we identify composers by a set of particular frequencies?  Since each frequency corresponds to a particular note, such a method may help to unlock new insights on composers’ musical tendencies.

On a broader note we could also use frequencies to isolate particular genres of music.  Furthermore we could use frequencies to determine what makes particular musical combinations dissonant or harmonic.  By analyzing the frequencies of musical compositions we can gain quite a bit of quantitative insight into music.

What do you guys think?  Do you believe that this quantitative analysis into the frequency domain of musical signals would unlock previously hidden insights? If not do you think that music is best analyzed qualitatively and that quantitatively analyzing music would drain the mystique associated with it?

(For those interested frequency analysis plays an essential role in computer generated music.  One example of this is the Karplus-Strong algorithm which allows computers to synthesize notes associated with a plucked string).