Christmas is here! Keith McNulty called on his LinkedIn network to co-create a script to play Christmas tunes. After adding some notes myself, the R script on this github page now plays Jingle Bells. The final tune you can download here and the script I pasted below. Any volunteers to make Let it snow or Silent night?

• 2018/12/19: Keith combined the full Jingle Bells script and my snow animation into a video.
• 2108/12/20: Mark Burkey posted R Jingle Bells on YouTube as well as a versions of Silent Night (R script) and Let It Snow (Rscript).

if(!"dplyr" %in% installed.packages()) install.packages("dplyr")
if(!"audio" %in% installed.packages()) install.packages("audio")

library("dplyr")
library("audio")

notes <- c(A = 0, B = 2, C = 3, D = 5, E = 7, F = 8, G = 10)

pitch <- paste("E E E",
"E E E",
"E G C D",
"E",
"F F F F",
"F E E E",
"E D D E",
"D G",
"E E E",
"E E E",
"E G C D",
"E",
"F F F F",
"F E E E E",
"G G F D",
"C",
"G3 E D C",
"G3",
"G3 G3 G3 E D C",
"A3",
"A3 F E D",
"B3",
"G G F D",
"E",
"G3 E D C",
"G3",
"G3 E D C",
"A3 A3",
"A3 F E D",
"G G G G A G F D",
"C C5 B A G F G",
"E E E G C D",
"E E E G C D",
"E F G A C E D F",
"E C D E F G A G",
"F F F F F F",
"F E E E E E",
"E D D D D E",
"D D E F G F E D",
"E E E G C D",
"E E E G C D",
"E F G A C E D F",
"E C D E F G A G",
"F F F F F F",
"F E E E E E",
"G C5 B A G F E D",
"C C E G C5")

duration <- c(1, 1, 2,
1, 1, 2,
1, 1, 1.5, 0.5,
4,
1, 1, 1, 1,
1, 1, 1, 1,
1, 1, 1, 1,
2, 2,
1, 1, 2,
1, 1, 2,
1, 1, 1.5, 0.5,
4,
1, 1, 1, 1,
1, 1, 1, 0.5, 0.5,
1, 1, 1, 1,
4,
1, 1, 1, 1,
3, .5, .5,
1, 1, 1, 1,
4,
1, 1, 1, 1,
4,
1, 1, 1, 1,
4,
1, 1, 1, 1,
4,
1, 1, 1, 1,
3, 1,
1, 1, 1, 1,
1, 1, 1, 1,
1, 1, 1, 1,
1, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
1, 1, 0.5, 0.5, 0.5, 0.5,
1, 1, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
1, 0.5, 0.5, 1, 0.5, 0.5,
1, 0.5, 0.5, 1, 0.5, 0.5,
1, 0.5, 0.5, 0.5, 0.5, 1,
1, 0.33, 0.33, 0.33, 1, 0.33, 0.33, 0.33,
1, 1, 0.5, 0.5, 0.5, 0.5,
1, 1, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
1, 0.5, 0.5, 1, 0.5, 0.5,
1, 0.5, 0.5, 1, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
1, 0.33, 0.33, 0.33, 2)

jbells <- data_frame(pitch = strsplit(pitch, " ")[[1]],
duration = duration)

jbells <- jbells %>%
mutate(octave = substring(pitch, nchar(pitch)) %>%
{suppressWarnings(as.numeric(.))} %>%
ifelse(is.na(.), 4, .),
note = notes[substr(pitch, 1, 1)],
note = note + grepl("#", pitch) -
grepl("b", pitch) + octave * 12 +
12 * (note < 3),
freq = 2 ^ ((note - 60) / 12) * 440)

tempo <- 250

sample_rate <- 44100

make_sine <- function(freq, duration) {
wave <- sin(seq(0, duration / tempo * 60, 1 / sample_rate) *
freq * 2 * pi)
fade <- seq(0, 1, 50 / sample_rate)
wave * c(fade, rep(1, length(wave) - 2 * length(fade)), rev(fade))
}

jbells_wave <- mapply(make_sine, jbells$freq, jbells$duration) %>%
do.call("c", .)

play(jbells_wave)

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