Ernest McClain, in his Myth of Invariance, attaches great importance to a scale construction consisting of all positive integers less than or equal to an integer n belonging to the prime limit p, reduced to an octave, which can be termed yantra(p, n). This construction is interesting independently of any consideration of whether McClain's general thesis makes any sense. This idea can be extended to scales we may call yantgen(n, m), consisting of all divisors of n less than or equal to m reduced to the octave. This construction includes both the yantra and the Euler genus, since yantgen(n, n) = genus(n), whereas yantgen((p!)^n, n) = yantra(p, n).