The functionoccurs in one of Ramanujan's inversion formulas for elliptic integrals. In this article, a common generalization of the cubic elliptic functionsis given. The function g 1 is the derivative of Ramanujan's function (after rescaling), and χ 3 (n) = 0, 1 or −1 according as n ≡ 0, 1 or 2 (mod 3), respectively, and |q| < 1. Many properties of the common generalization, as well as the functions g 1 and g 2 , are proved.