Correlation Between Music Genres, Their Length and BPM, Research Paper Example

Introduction

Different music styles are characterized by different speeds of sound and different instrumentation. Electronic dance music tends to be faster sounding, while traditional ballet dance music tends to be slower. Furthermore, modern music has a traditional 4/4 meter, while classical music deviates from this normality (Sachs 1953). In the United States, a wide variety of music is currently popular, ranging from pop to alternative to rock to electronic to country. Pop music is an abbreviation from “popular”, and this genre can be traced back to the 1950s in the United States as a mixture of styles that merged from jazz, rock and roll, folk, and traditional popular music (Marty 1988). MTV has been shaping modern pop-music industry for the last three decades, with requirements stating that songs should be three minutes long and be approximately between 117-122 beats per minute (BPM), in order to both fit in with the music that is considered popular and high energy, and so that this music can be made more easily televised. However, while these requirements were put in place, it is possible that some music deviates from this expectation (Apel 1969).

Alternative pieces of music usually are four minutes long with BPM of 160, while alternative rock is of approximately the same length, but its speed is at a lower 120 BPM (Epstein 1995). 90-130 BPM is in commonly used in rock as well as its varieties, with the usual time of the song being four minutes. A four-minute length is also typical of electronic music, which feature speeds of 65-95 BPM, while country music is approximately three minutes with an average speed of 130-150 BPM. These are average statistics taken from the Internet, which will serve as my base hypothesis to my calculation of the correlation between the genre, length, and BPM of a song.

Statement

My research question states, “How does the length and BPM of a song vary according to genre?” It is hypothesized that genres with longer lengths will have a slower BPM and genres that generally have shorter songs will be characterized by quicker BPMs because this differential allows for relatively similar content to be presented in different amounts of time. The null hypothesis (H0) states that song length and BPM are independent, while the alternative hypothesis (H1) states that song length and BPM are not independent.

Materials and Methods

The correlation between different music genres and their lengths will be explored. All data was retrieved from Internet resources. The following steps will be taken:

• First, information regarding 5 songs from 5 different genres were retrieved and their lengths and BPMs were determined.
• Second, descriptive statistics were used to determine the mean BPM and mean time of each genre.
• Third, a Chi-square test was conducted to determine the relationship between song length and BPM. The purpose of the Chi-square is to determine the relationship between the variables.

Predictions

Table 1: Genre and expected length and bpm.

According to the information presented in table 1, it was expected that pop, alternative, and country music would be shorter because they are typically the genres seen in the mainstream media. Meanwhile, it was predicted that rock music would be slightly longer because these musicians tend to fit more content into their music. Furthermore, classical music is typically longer, so it was predicted that this music would be 8 minutes long. It was expected that longer genres would have less BPM and shorter genres would have more BPM.

Data Presentation and Preliminary Analysis

Descriptive Analysis: Mean of BPM and Song Duration

Table 2: Genre and names of songs with singers.

The information presented in table 2 summarizes the names and genres of the songs utilized for this analysis.

Table 3: Pop songs BPM & length.

The information presented in table 3 presents the BPM and length of pop songs. The average length of the BPM for these songs is 107.4, while the average length of pop songs is 3 minutes and 46 seconds.

Table 4: Alternative songs BPM and length.

The information presented in table 4 presents the BPM and length of alternative songs. The average length of the BPM for these songs is 122.2, while the average length of alternative songs is four minutes even.

Table 5: Rock songs BPM and length.

The information presented in table 5 presents the BPM and length of rock songs. The average length of the BPM for these songs is 106.94, while the average length of rock songs is 4 minutes and 52 seconds.

Table 6: Country songs BPM and length.

The information presented in table 6 presents the BPM and length of country songs. The average length of the BPM for these songs is 112.8, while the average length of country songs is 3 minutes and 35 seconds.

Table 7: Electronic songs BPM and length.

The information presented in table 7 presents the BPM and length of electronic songs. The average length of the BPM for these songs is 134.4 while the average length of electronic songs is 3 minutes and 26 seconds.

Chi-Square Analysis

Table 8: Expected values of BPM and song duration for chi-square analysis.

Figure 1: Observed and expected duration of song for each genre in seconds.

After processing the data presented in figure 1, it was determined that the chi-square value equals 24.090 with 4 degrees of freedom. The two-tailed p-value was less than 0.0001, indicating that this value is statistically significant.

Figure 2: Observed and expected BPM of each song.

After processing the data presented in figure 1, it was determined that the chi-square value equals 20.977 with 4 degrees of freedom. The two-tailed p-value equals 0.0003, indicating that this value is statistically significant.

Evaluation

The null hypothesis (H0) stated that song length and BPM are independent, while the alternative hypothesis (H1) stated that song length and BPM are not independent. Since the chi-square test determined that the retrieved value was statistically significant, the null hypothesis can be refuted, supporting the concept that song length and BPM are dependent. Based on the data utilized in this experiment, it appears that the longest songs, such as classical music, have the least BPM and the longest length. However, it would be necessary to complete this data analysis using more data points in order to determine whether these findings hold true for all situations. Five songs per genre is a relatively small sample, so it would be valuable for future studies to evaluate this relationship on a broader scale.

Conclusion

In conclusion, the chi-square test demonstrated that the lengths of songs and BPM of songs by genre is statistically significant. This shows that it is likely that longer songs have a lower BPM, but it would be necessary to conduct further studies to confirm this understanding.

Bibliography

Apel, Willi. Harvard Dictionary of Music, Second Edition, Revised and Enlarged. The Belknap Press of Harvard University Press, Cambridge, Massachusetts, 1969.

Epstein, David. Shaping Time: Music, the Brain, and Performance. New York: Schirmer Books, 1995.

Marty, Jean-Pierre. The tempo indications of Mozart. New Haven: Yale University Press, 1988.

Sachs, Curt. Rhythm and Tempo: A Study in Music History. New York: Norton, 1953.