Anyone attending to topics like "Psychophony" and generally to "Healing with sound and music" also comes across the "Solfeggio frequencies", an old six-scale which was used as early as the Middle Ages to intonate sacred chants. It has been rediscovered by the American scientist Dr. Len Horowitz. To use these healing frequencies for a contemporary music CD, some technical problems had to be solved in the music studio first: • Since these frequencies are pure sinusoidal tones that can have a rather annoying effect on the human ear when played for a longer time, a suitable method had to be found to embed and pack the sounds warmly and softly, as it were. • The tuning of the sounds that appeared on the entered frequency did not correspond with the usual pitches of the used instruments. Thus, each instrument had to be retuned and adjusted for each Solfeggio tone. First, the appropriate Solfeggio frequency was set at the frequency generator (oscillator). Then the tone and the respective frequency tuning were measured on the tuner. All the other instruments were set to this tone tuning. This complex musical opus was a comprehensive and complicated precision work. For the present album "SOLFEGGIO-4x", the following frequencies were selected: Frequency Tone Tuning Meaning 396 Hz G 3 444,8 Relief from anxiety and guilt 639 Hz D#4 451,7 Harmonious relations 528 Hz C 4 444,1 Wonder 963 Hz A#4 454,5 Completion The Solfeggio tone runs permanently on a basic volume and can only be heard in certain places for some time outside of the overall musical arrangement.