Trust me. If you are interested in American opera or local history, you won’t want to miss this one.

Just in time for Thanksgiving, I’ll be sitting in for Sandy Steiglitz on WPRB’s Sunday Morning Opera with Sandy to host a rare broadcast of Romeo Cascarino’s “William Penn.”

Cascarino, born in South Philadelphia in 1922, labored at this, his magnum opus, for 25 years, from 1950 to 1975. It was given its premiere at the Academy of Music in Philadelphia in 1982, to mark the 300th anniversary of the founding of the city. Metropolitan Opera singer bass-baritone John Cheek assumed the title role, and Christopher Macatsoris conducted the Philadelphia Singers and the Chamber Orchestra of Philadelphia.

I will be joined in the studio by a very special guest: Dolores Cascarino, the composer’s widow, who created the role of Gulielma (as Dolores Ferraro), Penn’s wife. She will offer anecdotes about – and insights into – this beautiful and haunting opera.

I’ve said it before, and I’ll say it again: if Cascarino had completed “William Penn” within a few years of starting it, in the 1950s, the opera would now be mentioned in the same breath as Carlisle Floyd’s “Susannah” and Robert Ward’s “The Crucible.” It’s that good.

Join me for this one-of-a-kind broadcast of a first-rate, virtually unknown American opera, in a recording which is not commercially available, with valuable insights from the composer’s closest confidante, who sang in the work’s first performance.

It all comes your way on this week’s “Sunday Morning Opera,” which will be heard from 7 to 10 a.m. EST, on WPRB 103.3 FM and at wprb.com.