NASHVILLE — Jan Howard, a pioneering woman in country music who wrote and sang about heartache and experienced it herself, died on Saturday at her home in Gallatin, Tenn., near Nashville. She was 91.

Her son, Carter, said the cause was pneumonia.

Ms. Howard broke into country music at a time when scarcely a handful of women — Kitty Wells, Patsy Cline and Loretta Lynn among them — were consistently placing singles on the charts.

Originally a demo singer for songs intended for the likes of Ms. Wells and Ms. Cline, Ms. Howard had 20 hit singles in the country Top 40 from 1960 to 1972. Most were made for Decca Records under the renowned producer Owen Bradley.