Section 26.6 Rules of Spacing
Generally, the upper three voice parts (soprano, alto, and tenor) are kept close together. The general rule of spacing is to keep the distance between soprano and alto as well as the distance between alto to tenor within an octave of each other. Allowing a distance greater than an octave between soprano and alto (or between alto and tenor) is considered spacing error. The distance from the bass to the tenor can be greater than an octave.
In terms of spacing chords, one should consider the spacing that occurs in the overtone series.
Larger spaces between notes occur lower in the overtone series. Consider the voicings of the following chords. Some “ring” or resonate better than others. Notice that all of the notes fall within the voice ranges specified above.