View source for 173zpi

173 Zeta Peak Index (abbreviated 173[[zpi]]) is the [[Equal-step tuning|equal-step]] [[tuning system]] derived from the 173rd peak of the [[The Riemann zeta function and tuning|Riemann Zeta Function]].

== Theory ==
173zpi is the strongest [[Zeta peak index|zeta peak]] within ±0.5 [[EDO|divisions]] of [[39edo]], and serves as a [[Stretched and compressed tuning|compressed-octave]] version thereof ([[2/1]] ≈ 1196.204¢), narrowing the octave by ~3.796¢. 39edo approximates [[Just intonation]] rather poorly for its size, enough to designate it as a [[zeta valley edo|zeta ''valley'' EDO]], so using 173zpi instead—the strongest zeta ''peak'' within 39edo's vicinity—is a logical way of correcting for this, if desired.