Controls the note lengths. Length gives the initial value for the note length. If it is 70, then the actual note length is 70 percent of the value generated by the compiler. variation controls how much the length varies in percents, and smoothness controls the brownian noise smoothness. (legato 70 10 0.1) generates a note which length is 70 +-10 percent (60-80 percent) of the note generated by the compiler. In other words, if the compiler generates a 1/1 note, then the actual note length is 60-80 percent of it, and if the note is 1/16, the actual value is also 60-80 percent of it. If he optional vector-pattern is supplied then it replaces the brownian noise. This way you can use any data to control the legato values.