Complex sentence: Baird orients the approach around the interval of the perfect fifth and major third and claims that these intervals are the next most consonant intervals to the octave, as they are the first intervals in the overtone series to utilize a pitch different from the fundamental.
Split into simpler sentences: Baird orients the approach around the intervals of the perfect fifth and major third. He claims that these intervals are the next most consonant intervals to the octave, as they are the first in the overtone series to utilize a pitch different from the fundamental.