The author's advice is fantastic for learning a specific song, note for note as written. @MrGrando is smart to point out that Jazz and other forms of music are much more about free expression and improvisation. A level above the author's practice would be to start understanding the structure of the piece from a music theory standpoint. The relationship between the notes becomes the important element and you begin to see things like a II V I chord progression. By understanding the structure, you realize you can improvise on implied scales, transpose to other keys and harmonize with new chords to add your own creativity.