Ask Mr. Smarty Plants

Second, and what you really are most interested in, Mr. Smarty Plants doesn't know if music affects the growth of necklace pod plants or any other plants for that matter.  This, however, has been a very popular topic for science fairs.  The problem is that for a science fair project you aren't going to be able to run an experiment that can definitively tell you "yes" or "no". There are too many variables that can interfere.  The popular Discovery Channel TV show, Mythbusters, ran their own experiment to test this and concluded that it is "plausible" that talking helps plants grow.  They also determined that classical music and heavy metal music  made the plants grow better than the control plants that received neither talk nor music. However, David R. Hershey, a botanist and biology education specialist, points out the many errors on the Mythbuster's Experiment on Talking and Music Effects on Plant Growth and demonstrated the pitfalls of conducting a necessarily simple experiment on a complex question.  These pitfalls also await students who are likely have a lot fewer resources to do experiments than Mythbusters did. 

If you have done some searching on the internet, you have probably found references to the The Sound of Music and Plants by Dorothy Retallack.  She wrote that her experiments with plants and music showed that plants respond to different kinds of music—classical music has positive effects and rock music has negative effects (not the same results that the Mythbusters found!).  However, at least one scientist (Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University) questions the science of her experiment and cites this book as a prime example of 'bad science' in her article, The Myth of Absolute Science ("If it's published, it must be true").

So, there is some flawed or pseudoscience out there indicating that music affects the growth of plants.  Is there any real science? There is some indication that sound waves (music is comprised of sound waves) can have an effect on plants—Frank Telewski in his article A Unified Hypothesis of Mechanoperception in Plants, pp. 1468-1469 [American Journal of Botany 93(10):1466-1476. 2006] gives a brief summary of published researchon the effects of sound on plants.  There is another article by Katherine Creath and Gary E. Schwartz,  Measuring Effects of Music, Noise, and Healing Energy Using a Seed Germination Bioassay,  [Journal of Alternative and Complementary Medicine, 10 (1):113-122.  2004] that reported music increased seed germination in two plants.  David R. Hershey in [Plant-education] Re: effect of noise pollution on metabolism of plants points out that the authors and experimenters for this article aren't botanists.

Finally, here is a critique on Science Projects on Music and Sound by Professor Ross E. Koning, a botanist, from Eastern Connecticut State University on the Plant Physiology Information Website.

The bottom line is that if you are all set up to do your experiment using Sophora tomentosa (yellow necklacepod) as your experimental plant, you need to realize that you aren't going to be able to precisely control all the variables that can affect the growth of your plants (light, water, extraneous sounds, etc.) and you probably won't have too many replications of the plants to work with.  However, you should plan your experiment and conduct it as carefully as you can and write up the results acknowledging the factors that might have influenced your final results.

For your next science fair project, you might do a litte more research before you choose a topic to ensure that it is not quite as complex as this one.