Four Tops lead singer Levi Stubbs, one of the defining voices of Motown Records in the 1960s, died Friday at his home in Detroit. He was 72.

No cause of death was given but Stubbs had had a series of illnesses, including a stroke that he suffered in 2000, five years after he had been diagnosed with cancer.

In the Motown Records stable of smooth male crooners, Stubbs was the chief anomaly. His baritone was more distinctively rich and gravelly than his Detroit peers; emotional rawness was his stock in trade on such hits as “I Can’t Help Myself (Sugar Pie, Honey Bunch),” “Ask the Only” and “Reach Out, I’ll Be There.”

And unlike other key Motown stars, Stubbs never opted to record as a solo act, remaining with the Four Tops for nearly 50 years. The group — Stubbs (born Stubbles), Renaldo “Obie” Benson, Lawrence Payton and Abdul “Duke” Fakir — was formed while the members were in high school in 1954 and remained intact until Payton died in 1997. Benson died in 2005.

Overall they had 45 pop hits, including “Reach Out,” “Standing in the Shadows of Love” and “Ain’t No Woman Like the One I’ve Got.” Their first No. 1 single, “I Can’t Help Myself (Sugar Pie, Honey Bunch),” came in 1965.

Originally calling themselves the Four Aims and singing jazz, they became the Four Tops in 1954 and signed with Chess Records in Chicago in 1956. While their jazz-oriented records, issued by Red Top, Riverside and Columbia, never sold, the group was able to make a living playing top clubs.

Even in their earliest years, the trademark of the group was Stubbs’ attempt to squeeze his baritone into the role of a tenor, which gave the vocals a pleading quality. The jazz act got them booked on “The Tonight Show” in 1963 doing a jazz arrangement of “In the Still of the Night.”

That performance led Berry Gordy to reach out to the act and get them in the studio, where they made a jazz album that was never released. Gordy then assigned the group to songwriters Brian Holland, Lamont Dozier and Eddie Holland, and they promptly came up with “Baby I Need Your Loving,” which hit No. 11 on the pop chart in 1964. The ballad instantly sealed their trademarks: Stubbs’ searing vocals, harmonies enhanced with female voices and a churning sound generated by the backing band to create tension underneath the voices.

The band’s evolved alongside that of Holland-Dozier-Holland, charting with “Bernadette” and “Seven Rooms of Gloom” in 1967. When the writers departed, the Four Tops turned to covers such as Tim Hardin’s “If I Were a Carpenter” and “River Deep — Mountain High,” and worked with other inhouse producers and songwriters on “Still Water (Love).” Like the Temptations and Supremes, the Four Tops also added choreography to their act.

Entrenched in Detroit, the band left the Motown label when Gordy moved its headquarters to Los Angeles, signing with ABC/Dunhill, where they struck gold with “Ain’t No Woman Like the One I’ve Got” in 1973, and later Casablanca, which released “When She Was My Girl” in 1981.

A joint appearance with the Temptations on 1983’s Motown 25th anniversary TV special sparked a career revival as the two acts toured the world together for three years after that. The tour included a string of concerts on Broadway.

Always popular in the U.K., they had another resurgence in 1988 with “Indestructible” and “Loco in Acapulco.”

The group was inducted into the Rock and Roll Hall of Fame in 1990.

Stubbs, who declined the role played by Billy Dee Williams in “Lady Sings the Blues,” eventually added acting to his resume by supplying the voice of a man-eating plant, Audrey II, in the 1986 musical film “Little Shop of Horrors” and Mother Brain on the cartoon show “Captain N: The Game Master,” from 1989 to 1991.

Stubbs is survived by his wife of 48 years, Clineice; five children, Deborah, Beverly, Raymond, Kelly and Levi Jr.; and 11 grandchildren.