The octave is a fundamental part of nearly all musical scales.  How accurate is your perception of it?


The frequency ratio between two tones that are an octave apart is 2:1.  Orchestras tune to an A at 440 Hz.  One octave above that is 880 Hz, one octave below is 220 Hz. Initially this simple relationship might seem particularly easy to perform.  In practice, however, octaves can be particularly difficult for singers and orchestras to tune, both simultaneously and sequentially.  The audience is so sensitive to slight differences in this ratio that even the smallest variation can sound dissonant.  Our sensitivity can be useful, however, when a skilled artist bends and shapes the notes to evoke emotion.  For example, the opening notes of "Somewhere over the Rainbow" are an octave (the "somewhere" part).  You can hear how differently Judy Garland and Jewel sing this song--each taking advantage of how easily you can hear the octave.  Note: each clip takes about 10 seconds to download.


Here's a less musical example of an octave.  The first note is 220 Hz, and the second is 440 Hz.  Listen for octaves, this time played by various instruments, in this clip of Take Me Out to the BallgameNote: please be patient as the clips download (about 10 seconds each).


Testing your perception...

Listen to the samples as many times as you like, and then check whether you think it is an octave or not.  After you complete the set, press the "Register" button beside the table to see your accuracy.  Keep trying until you score at least in the 80's--listen carefully!  With 8 samples, each is worth 12.5 percentage points.


Choose the octaves












Sample #1









Sample #2









Sample #3







Sample #4



Percent correct






Sample #5







Sample #6







Sample #7



Sample #8





you're accepting 

octaves that are





How accurate is your perception of the octave?  

If you made any errors, did you tend to accept octaves that were too low or too high?

Does your performance improve with repetition? Comment.