This unusual box CD came from the private collection of a national entertainment correspondent. Johnny Mathis signed it during one of their many interviews in his Hollywood Hills home.

What do Billie Holiday, the Temptations, Johnny Mathis, Lena Horne and Nina Simone all have in common? They were among many black American artists who sang Jewish songs. And their rarely told American story is chronicled on a new compilation called "Black Sabbath: The Secret Musical History of Black-Jewish Relations", which uses music to connect these two seemingly disparate groups.

There's Cab Calloway mixing Yiddish into his scatting during "Utt-Da-Zy" and Eartha Kitt's orchestrated delivery of "Sholem Aleichem." There's even the Temptations with a medley from "Fiddler On the Roof" and Aretha Franklin singing "Swanee". The most moving of these 15 tracks is a rare gem from Johnny Mathis.

In 1958, one of the four albums Mathis recorded was "Good Night, Dear Lord," a collection of religious songs dedicated to his mother. Amid the expected Christian music — from spirituals ("Swing Low, Sweet Chariot," "Deep Night") to formal pieces ("The Rosary," two versions of "Ave Maria") — were three Jewish songs: the Yiddish hymn "Eli Eli"; a song about a Warsaw ghetto, "Where Can I Go?"; and the Yom Kippur prayer chant "Kol Nidre." It's the latter that features on "Black Sabbath." Rarely have we heard Mathis sing with such pathos.

"People ask me to explain why someone like myself would get involved with religious Jewish music," Mathis says. "It's the way you're brought up. Me, growing up in San Francisco, I had this extraordinary opportunity to listen to all kinds of music and studied voice for seven or eight years with a wonderful teacher. She first introduced me to it. As a singer, when you hear something extraordinary like that — and a lot of Jewish music is musically quite challenging — you want to sing it, you want to at least try it, to see if you can do it."

"Black Sabbath: The Secret Musical History of Black-Jewish Relations" is a musical journey through a unique slice of recording history, marking the musical connections and collaborations between black and Jewish musicians throughout history. It includes a brilliant 52-page booklet that provides a detailed history and analysis of the relationships, making it a valuable resource for anyone interested in the intersection of music and culture.