Code Along for Rhythmic Analysis of Music Genres using R Programming

Step 1: Data Collection

To collect data using the Spotify API, you will need to install and load the httr package in R. You will also need to create a Spotify developer account and obtain an API key. Replace 'YOUR_API_KEY' with your actual API key.

install.packages("httr")
library(httr)

# Set your API key
api_key <- 'YOUR_API_KEY'

# Make a GET request to the Spotify API to retrieve song data
response <- GET(
  url = 'https://api.spotify.com/v1/tracks',
  query = list(
    limit = 50,  # Number of songs per genre
    market = 'US',
    seed_genres = 'rock',  # Replace with the genre of your choice
  ),
  add_headers('Authorization' = paste('Bearer', api_key))
)

# Print the response
print(content(response))

Explanation:

  • The httr package is used to make HTTP requests to the Spotify API.
  • You need to set your API key by replacing 'YOUR_API_KEY' with your actual API key.
  • The GET() function is used to make a GET request to the Spotify API.
  • The url parameter specifies the endpoint URL for retrieving tracks.
  • The query parameter is a list of query parameters to include in the request. In this case, we specify the limit, market, and seed_genres parameters.
  • The add_headers() function is used to add the Authorization header with the API key.
  • The content() function is used to extract the content of the response.

Step 2: Data Preprocessing

For data preprocessing, you will need to install and load the tidyverse package in R. Assuming you have stored your song data in a dataframe called song_data, which includes the columns ‘song_name’, ‘genre’, and ‘bpm’, you can use the following code to clean the data.

install.packages("tidyverse")
library(tidyverse)

# Remove rows with missing values
cleaned_data <- song_data %>% na.omit()

# Remove outliers using the interquartile range (IQR) method
cleaned_data <- cleaned_data %>%
  filter(bpm >= quantile(bpm, 0.25) - 1.5*IQR(bpm) & bpm <= quantile(bpm, 0.75) + 1.5*IQR(bpm))

# Print the cleaned data
print(cleaned_data)

Explanation:

  • The tidyverse package is a collection of R packages for data manipulation and visualization.
  • The na.omit() function is used to remove rows with missing values from the song_data dataframe.
  • The filter() function is used to remove outliers from the bpm column using the interquartile range (IQR) method.
  • The quantile() function is used to calculate the lower and upper bounds for the IQR method.
  • The cleaned data is stored in the cleaned_data dataframe.
  • The print() function is used to display the cleaned data.

Step 3: Statistical Analysis

For statistical analysis, you can use built-in R functions. Assuming you have cleaned your data and stored it in a dataframe called cleaned_data, which includes the column ‘genre’ for the different music genres and ‘bpm’ for the beats per minute, you can use the following code to calculate descriptive statistics and perform ANOVA.

# Load required packages
library(tidyverse)
library(stats)

# Descriptive statistics
summary_stats <- cleaned_data %>%
  group_by(genre) %>%
  summarise(
    mean_bpm = mean(bpm),
    median_bpm = median(bpm),
    sd_bpm = sd(bpm)
  )

print(summary_stats)

# One-way ANOVA
anova_result <- aov(bpm ~ genre, data = cleaned_data)
print(summary(anova_result))

Explanation:

  • The tidyverse and stats packages are loaded for data manipulation and statistical analysis.
  • The group_by() function is used to group the data by genre.
  • The summarise() function is used to calculate the mean, median, and standard deviation of BPM for each genre.
  • The aov() function is used to perform a one-way ANOVA with BPM as the dependent variable and genre as the independent variable.
  • The summary() function is used to display the summary statistics and ANOVA results.

Step 4: Data Visualization

For data visualization, you will need to install and load the ggplot2 package in R. Assuming you have stored your cleaned data in a dataframe called cleaned_data, you can use the following code to create boxplots and a bar plot.

install.packages("ggplot2")
library(ggplot2)

# Boxplots
boxplot <- ggplot(cleaned_data, aes(x = genre, y = bpm)) +
  geom_boxplot() +
  labs(title = "Rhythmic Analysis of Music Genres",
       x = "Genre",
       y = "Beats Per Minute") +
  theme_bw()

print(boxplot)

# Bar plot
barplot <- ggplot(summary_stats, aes(x = genre, y = mean_bpm)) +
  geom_bar(stat = "identity") +
  labs(title = "Mean Beats Per Minute by Genre",
       x = "Genre",
       y = "Mean Beats Per Minute") +
  theme_bw()

print(barplot)

Explanation:

  • The ggplot2 package is used for creating visualizations in R.
  • The ggplot() function is used to initialize a plot object.
  • The aes() function is used to specify the aesthetic mappings, such as the x and y variables.
  • The geom_boxplot() function is used to create boxplots of BPM for each genre.
  • The geom_bar() function with stat = "identity" is used to create a bar plot of mean BPM for each genre.
  • The labs() function is used to add titles and axis labels to the plots.
  • The theme_bw() function is used to set a black and white theme for the plots.
  • The print() function is used to display the plots.

Step 5: Interactive Visualization

For creating an interactive visualization, you will need to install and load the shiny and shinydashboard packages in R. You can use the following code as a starting point to create an interactive app.

install.packages("shiny")
install.packages("shinydashboard")
library(shiny)
library(shinydashboard)

# Define UI
ui <- dashboardPage(
  dashboardHeader(title = "Rhythmic Analysis of Music Genres"),
  dashboardSidebar(
    sidebarMenu(
      menuItem("Interactive Plot", tabName = "plot")
    )
  ),
  dashboardBody(
    tabItems(
      tabItem(
        tabName = "plot",
        fluidRow(
          box(
            title = "Genre",
            selectInput(
              inputId = "genre",
              label = "Select a genre:",
              choices = unique(cleaned_data$genre)
            )
          ),
          box(
            title = "Histogram",
            sliderInput(
              inputId = "bins",
              label = "Number of bins:",
              min = 10,
              max = 50,
              value = 30
            )
          )
        ),
        fluidRow(
          plotOutput(outputId = "histogram")
        )
      )
    )
  )
)

# Define server
server <- function(input, output) {
  output$histogram <- renderPlot({
    genre_data <- cleaned_data %>%
      filter(genre == input$genre)

    ggplot(genre_data, aes(x = bpm)) +
      geom_histogram(bins = input$bins, fill = "steelblue", color = "white") +
      labs(title = paste("Histogram of Beats Per Minute for", input$genre),
           x = "Beats Per Minute",
           y = "Count") +
      theme_bw()
  })
}

# Run the app
shinyApp(ui = ui, server = server)

Explanation:

  • The shiny and shinydashboard packages are loaded for creating an interactive app.
  • The dashboardPage(), dashboardHeader(), dashboardSidebar(), and dashboardBody() functions are used to define the layout of the app.
  • The menuItem() function is used to create a menu item for the interactive plot.
  • The fluidRow() and box() functions are used to create a responsive layout for the inputs and outputs.
  • The selectInput() function is used to create a dropdown menu for selecting a genre.
  • The sliderInput() function is used to create a slider for adjusting the number of bins in the histogram.
  • The plotOutput() function is used to create a placeholder for the histogram plot.
  • The renderPlot() function is used to generate the histogram plot based on the selected genre and number of bins.
  • The ggplot() function and other ggplot2 functions are used to create the histogram plot.
  • The paste() function is used to dynamically generate the title of the histogram plot based on the selected genre.
  • The theme_bw() function is used to set a black and white theme for the plot.
  • The shinyApp() function is used to run the app.

Remember to replace 'YOUR_API_KEY' with your actual Spotify API key.

These code snippets provide a starting point for your project. Feel free to explore and experiment with different R packages and techniques to further enhance your analysis and visualizations.