install.packages("Hmisc")
library("Hmisc")
summary(cut2(x$plays, g=5))

> summary(cut2(x$plays, g=5))
[ 1,  5) [ 5, 11) [11, 25) [25, 52) [52,833] 
9040     7104     8458     7784     7902

> xn <- subset(x$plays, x$plays >= 5 & x$plays <= 11)