This lesson is on the "Glowing Tones Strategy." Glowing tones are notes that set off resonant tones/sympathetic vibrations on your instrument. A good example is the low G on the E string - when played in tune, your open G string will vibrate, and you can often hear the D string ringing as well.
I have included two PDFs by Dennis Whittaker on the concept of Glowing Tones, which you can find below. One is his explanation and use of Glowing Tones, and the other is his version of the original Suzuki exercise, which he adapted for bass. If you want to learn more about him check out this superb interview with Jason Heath of Contrabass Conversations.
This concept is discussed in Suzuki's book, "Tonalization". You can find a link to purchase the book here.
This lesson is taken from Lauren Pierce's new course 'Practiceology', your guide to creating your perfect practice routine.