Hi bongglee. The music for the improvisations is not written down. Those videos are M. Delcamp's examples of how you might improvise in various ways on the basic chord pattern of the piece SCHIARAZULA MARAZULA, which is now on page 8 of the D03 scores. He describes what you should do in the text of his lesson.
By the way, please note that if you wish to take part in these lessons you should join the Online Students group and fulfil the conditions for taking part, as described here: viewtopic.php?f=41&t=54023
This includes changing your name if necessary to one that includes your first name, publicizing the lessons, and confirming that you have done so in this thread: viewtopic.php?f=41&t=54023
Classical Guitar Forum.
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