A swing rhythm can be created by tying together the first and second notes of an eighth note triplet. Play Exercise 66 which contains triplets.
Exercise 67 has the first and second notes of the triplet group tied. Do not play the second note of the triplet group. Play the first and third notes only. This gives the exercise a "swing feel".
The two eighth note triplets tied together in Exercise 67 can be replaced by a quarter note.
To simplify notation, it is usual to replace the z with 6, and to write at the start of the piece, 6 = z as illustrated in Exercise 69.
Exercises 67, 68 and 69 sound exactly the same, but are just written differently.
On the recording there are three beats to introduce this song.