Intervals and ranges of the 4 basic voices of the harmony which are the soprano, the alto, the tenor and the bass. We usually begin the study of harmony by chords of four sounds or four "voices". In order to obtain a homogeneous chord of four voices, we need to respect the distances between two adjacent notes of the chord: -between bass and tenor, maximum interval is a twelfth. -between tenor and alto, maximum interval is the octave. -between alto and soprano, maximum interval is the octave too. Each voice has a range that we will respect.: For example, the range limits of the soprano is located between the "C3" and "A4." for the alto, the range is : "G2" to "E4". for the tenor, between "C2" and "A3". for the bass, between "Eb1" and "D3". Chord positions are chosen according to the register of the chord: In the first case, the perfect C major chord is placed in the lower register. This is possible but this sound can be improved. If we reverse the "Mi" note to the upper octave, we get the same chord in open position and the sound gets better. One can also have a bass note alone and the other three notes in the medium register. But we should avoid a single soprano in the high register, and all other notes of the chord being together in the low register. In the extreme low register, one should avoid intervals of third or fourth, sixth and seventh. The best intervals to use in this bass register are the fifth and the octaves.