As part of the lecture 'Theoretical background of audio and graphics', which deals with the basics of audio signal processing/audio production and computer graphics, students learn to produce their own musical piece and visualize it using computer graphics. The artistic basis is musique concrète. The pieces of the CTech classes are bundled and presented here as a CTech Online Album. Any further use of the presented content has to be agreed upon with the responsible persons. If you have any questions, please contact Prof. Angela Brennecke (a.brennecke@filmuniversitaet.de) Enjoy the music!