<birthday singing clip> Ever noticed how when a big group sings "Happy Birthday," the beginning is a jumbled mess, with everyone singing a slightly different pitch? But then, near the end, it all sort of comes together?

That's because we tend to adjust our own singing pitch to accommodate others. And now scientists in the U.K. have found that even trained choral singers will follow their fellow choir members. But not necessarily in the right direction.  

The researchers had eight pairs of musically trained amateur singers—all women for this study—sing, a capella, the melody of either "Silent Night" <clip> or another classic choir tune, "O Sacred Head, Now Wounded."<clip>

Individual volunteers all sang in their own separate studios, under four different scenarios: each singer was completely isolated, hearing only themselves; or singer one got to hear singer two <left ear solo>; or singer two got to hear singer one <right ear solo>; or finally, both singers could hear each other <stereo harmony>. Then the researchers used software to extract pitch information from the recordings. 

What they found was that singers stayed more on tune with the pitch written in the musical score when singing solo, versus singing with a partner. And when one partner veered off pitch, the other singer followed her, perhaps to compensate for the error—meaning even though they weren’t singing the pitch as written, the resulting duet was more harmonious. The findings are in the Journal of the Acoustical Society of America. [Jiajie Dai and Simon Dixon, Singing together: Pitch accuracy and interaction in unaccompanied unison and duet singing]

The results support a common practice in choirs: put weak singers next to strong ones, so they can follow their pitch. As for the rest of us amateurs, if you find yourself out at karaoke duetting with an off-pitch friend, take this advice from study author Jiajie Dai of Queen Mary University of London: 

"You have to listen to yourself more than you listen to others. Trust yourself, never depend on others." This guideline appears to be the key…to staying on key. 

—Christopher Intagliata

[The above text is a transcript of this podcast.]