SAMPLE EXPERIMENTAL RESEARCH PAPER

Introduction
Music is present in many cultures around the world and is enjoyed by both humans and animals. Some initial research has explored how music affects humans psychologically and physically. Little research has examined the impact of different types of music on plant growth and development. If music is found to significantly influence plant growth, it could have applications for the agricultural industry to help boost crop yields. The purpose of this experimental research was to investigate the effects of three different music genres—classical, pop, and heavy metal—on the growth of bean plants over a three-week period.

Literature Review
A few prior studies have investigated the relationship between music and plant growth. One study by Yao and colleagues (2018) exposed chrysanthemum plants to different types of classical music for 30 minutes per day over a three-week period. They found that chrysanthemums exposed to Vivaldi’s “Spring” grew taller and had more leaves and flowers compared to the control group that was not exposed to music. Another study by Zhang and colleagues (2015) played Baroque classical music at 80 decibels for 3-6 hours daily to pea and wheat seedlings. They observed increased growth and chlorophyll content in the plants exposed to the music compared to controls. Their study did not investigate other music genres like pop or heavy metal.

More research is still needed to determine if all music genres have beneficial effects or if certain types are more effective than others. Music varies considerably in tempo, instruments used, melody, harmony, and other attributes. These differences could influence plant growth to varying degrees. Heavy metal music in particular contains fast tempos, distorted guitars, screaming vocals, and power chord progressions that are much different acoustically than classical and many pop songs. It remains an open question as to whether plants would respond positively or negatively to heavy metal. The current study aims to address this gap by directly comparing the impacts of classical, pop, and heavy metal music on bean plant growth over a multi-week period.

Hypotheses
Based on prior research showing positive plant growth effects of classical music, it was hypothesized that:

H1: Bean plants exposed to classical music will demonstrate increased growth, as evidenced by greater increases in height, number of leaves, and leaf area, compared to control plants not exposed to music.

Given that pop music contains less abrupt changes in tempo and dynamics than heavy metal but more complex melodies and harmonies than classical, it was further hypothesized:

H2: Bean plants exposed to pop music will exhibit greater growth than control plants but less growth than plants in the classical music condition.

Finally, due to heavy metal music’s distortion, fast tempos and aggression in tone, it was hypothesized:

H3: Bean plants exposed to heavy metal music will demonstrate decreased growth or health compared to control plants and plants in the other music conditions as a result of the disruptive acoustic properties of heavy metal.

Method

Participants and Materials
Sixty common green bean (Phaseolus vulgaris) seeds were obtained from a local nursery. The seeds were potted individually in plastic 6 oz pots containing potting soil. Twelve pots each were assigned randomly to four different music exposure conditions: classical, pop, heavy metal, and a no-music control condition.

The classical music used was Vivaldi’s “Four Seasons.” The pop music selection was Adele’s “Rolling in the Deep.” The heavy metal music was “Master of Puppets” by Metallica. All music was played at a volume of 70 decibels, as measured by a digital sound level meter, for 2 hours daily between 10am-12pm over 21 days. A portable Bluetooth speaker was used to play the music.

A ruler and scale were used to measure plant height and leaf size, respectively. A data recording sheet was used to record measurements each week.

Procedure
Seeds were watered regularly and given sufficient sunlight through a greenhouse setting. On days 1-21 of the experiment, the pre-selected classical, pop, or heavy metal songs were played on loop for 2 hours to each respective potted plant condition, while the control plants received no music exposure.

Once per week for 3 weeks, all plants were measured for height (cm) from the soil to the highest point of the main stem. The number of leaves and total leaf surface area (cm2) were also recorded on each measurement date. Any signs of wilting, spots, or other damage on the leaves were noted as well for health assessment purposes.

Data Analysis
A one-way ANOVA was conducted to compare the effects of the different music conditions (classical, pop, heavy metal, control) on plant height, number of leaves, and total leaf area after 3 weeks. Any significant effects were followed up with post-hoc Tukey tests to determine which groups differed. Statistical significance was set at p < .05. Results Plant Height The one-way ANOVA revealed a statistically significant effect of music condition on plant height after 3 weeks, F(3, 56) = 4.35, p = .008. Post-hoc Tukey tests showed the classical music plants (M = 17.50 cm, SD = 2.81) were significantly taller than both the control plants (M = 14.17 cm, SD = 1.94) and heavy metal plants (M = 13.83 cm, SD = 3.28), ps < .05. The pop music plants (M = 15.58 cm, SD = 2.79) did not statistically differ from any other group. These results support hypothesis 1 that classical music enhances growth. Number of Leaves There was also a significant effect of music condition on leaf number, F(3, 56) = 3.24, p = .029. Specifically, plants exposed to classical music had developed significantly more leaves (M = 14.33, SD = 2.07) than control plants (M = 11.75, SD = 1.48) and heavy metal plants (M = 12.08, SD = 2.44), ps < .05. Leaf count did not differ between pop music plants (M = 13.25, SD = 1.48) and any other group. These findings again demonstrate classical music's benefits and reject hypothesis 3 regarding heavy metal. Leaf Area For total leaf area after 3 weeks, the ANOVA yielded a marginally significant effect of music condition, F(3, 56) = 2.56, p = .063. Though not quite achieving significance, leaf area measurements followed the same overall trend, with classical music plants (M = 110.78 cm2, SD = 19.50) evidencing the largest size, followed by pop (M = 102.26 cm2, SD = 18.46) then control (M = 94.70 cm2, SD = 14.28) and heavy metal (M = 90.27 cm2, SD = 21.15) conditions. These partial results lend partial support to hypotheses 1 and 2 about classical and pop music promoting greater growth than controls. Health Assessment No noticeable leaf damage, spots, or wilting was seen among any plants, indicating all were in healthy condition regardless of music condition.