The challenge for overtone singers here is especially the intonation conflict of the natural overtone thirds with the equal-tempered ones of the piano. In this version, I have partially adjusted the overtones to match the equal-tempered tuning, resulting in “out of tune” fundamental tones. The alternative of intonating the harmonics in relation “out of tune” is found by some to be cleaner overall. An interesting experiment. Piano and overtones never fit together exactly because, except for the octave, none of the piano intervals correspond to the natural harmonic order. I think it sounds delightful nonetheless.