# => Define the variable with the [This's the "best" music] string
message <- "This's the \"best\" music"
message <-gsub("\"", "\\\"", gsub("\'", "\\\'", message, fixed=TRUE), fixed=TRUE)
cat(message, sep="\n")

cat(gsub("([\"'])", "\\\\\\1", "This's the \"best\" music"), sep="\n")