Can sympathetic vibrations create vocal undertones in acoustic environments?

[grannymama]

Hello! Sorry, I don't have much of a formal education, but am an amateur singer (female, age 66, tenor) who experienced a BIG surprise during one of our choral concerts a few weeks ago. While a fellow tenor was singing a solo (Gounod "Sanctus"), I heard distinct undertones (fourths). I was so shocked I lost my place in the music (but quickly recovered). At my age, I have heard overtones many times, but this was a first! The concert venue was a stone church in the VA. countryside; the undersides of the roof stones were exposed into the church's interior. Once, during a rehearsal there, the acoustics were so exquisite I burst into tears. Whew! Was I really hearing undertones, or was it just a miraculous moment of transcendence? Whatever it was, I will NEVER forget it! Thanks for your advice.

 

[Doc Al]

< Moved to General Physics >

 

[lzkelley]

For simple sounds (the vast majority) the fundamental is the loudest and easiest to produce. What that fundamental note is, is dependent on the material, and complex situations creating the vibration.
Sometimes, however, the fundamental is not the most prominent sound -> ussually in very complex resonance situations. What i suspect, is that the vocals you ussualy hear from this person, (or maybe everyone) are actually overtones, that because of the complex situation in the vocal cavity and chords are much louder than the fundamental -> but for some reason at this particular location the actual lowest notes being produced (the fundamental(s) ) were amplified - and seemed to be undertones.

In a way, i think it comes down to your definition of an undertone. A physicist would most likely define an undertone as a frequency lower than the fundamental (which is impossible -> hence my explanation); while a musician would define an undertone as one below the loudest / most-prominent / most common.
I play the saxophone, most of the notes i play are in a certain range of frequencies. If i modify the opening from the bell (with my leg for instance) i can bring out "undertones" which are significantly lower that anything i can create in normal play. The fundamental frequency for the saxophone, is too low for the human ear which means that these "undertones" are still technically overtones; just overtones generally more subtle than the prominent notes.

 

[rcgldr]

Sympathetic vibrations could result in an "undertone", such as holding a lower note on a piano open while playing a note one octave above the open note.