Making a plot of a midi file

midiplot.R

library(ggplot2)
library(tuneR)

midi <- tuneR::readMidi("https://www.8notes.com/school/midi/piano/beethoven_ode_to_joy.mid")


df <- tuneR::getMidiNotes(midi)

# Difference between first two notes
mult <- 960

ggplot(df, aes(x = time / mult, y = note)) +
  geom_point() +
  geom_segment(
    aes(xend = time / mult + length / mult,
        yend = note)
  ) +
  scale_x_continuous(
    breaks = seq(0, max(df$time + df$length)/mult, by = 4),
    labels = function(x){x/4},
    name = "bars"
  ) +
  scale_y_continuous(
    breaks = function(x){
      x <- seq(x[1], x[2], by = 12)
      as.vector(outer(x, c(1,3,5,6,8,10,12), "+"))
    },
    labels = function(x){tuneR::notenames(-69:62)[x + 1]}
  ) +
  ggtitle(
    midi$parameterMetaSystem[midi$event == "Sequence/Track Name"][[1]],
    midi$parameterMetaSystem[midi$event == "Text Event"][[1]]
  )