NEW YORK — Pete Moore, an original member of the Miracles, the hitmaking Motown group led by Smokey Robinson, and a co-writer of some of that group’s hits, died in Las Vegas on Nov. 19, his 79th birthday.

His wife, Tina, said the cause was complications of diabetes.

Mr. Moore’s credits included three melancholy Top 20 hits that were released in 1965: “Ooo Baby Baby,’’ written with Robinson; “The Tracks of My Tears,’’ with Robinson and guitarist Marv Tarplin; and “My Girl Has Gone,’’ with Robinson, Tarplin, and the group’s Ronnie White.

Adam White, author with former Motown Records executive Barney Ales of “Motown: The Sound of Young America’’ (2016), said in an e-mail that this trilogy of Miracles songs “defines their talent and their art better than anything else.’’

He added, “A measure of Pete Moore’s importance to the Miracles lies in the personal: that he and Smokey were friends from childhood; that he was in the earliest incarnations of the group — and that he was the best man at Smokey’s wedding.’’

Mr. Moore brought his bass voice to a group known for its smooth harmonies, snazzy clothes, and silky onstage choreography, and for the good looks and angelic high tenor, which rose effortlessly to a falsetto, of its leader, Robinson.

In the origin story of the Motown empire, the Miracles were founder Berry Gordy Jr.’s first great ensemble, preceding the Supremes, the Four Tops, and the Temptations. “Shop Around’’ (1960), which Gordy wrote with Robinson, was Motown’s first million-seller, rising to No. 2 on the Billboard Hot 100 chart — thanks in part to the timing of its release.

In an interview in 2015 with WVUD-FM in Newark, Del., Mr. Moore said Gordy “wasn’t aware that you didn’t release records in December.’’

“The record came out on Dec. 17,’’ he continued. “Everybody was shopping. When they heard ‘Shop Around’ on the radio, that’s what they were doing — buying dresses and toys for the kids — and that record exploded. Wow! Bam!’’

There would be many more hits after that, including “You’ve Really Got a Hold on Me,’’ “Mickey’s Monkey,’’ “Going to a Go-Go’’ and, following a name change to Smokey Robinson and the Miracles in 1967, “I Second That Emotion’’ and “The Tears of a Clown.’’

Mr. Moore recalled that “The Tracks of My Tears’’ emerged from a guitar riff played by Tarplin that coincided with their desire to write a song inspired by the tragic opera “Pagliacci,’’ whose central character is a sad clown.

“Why don’t we write a song about a guy who appeared to be happy on the outside but he’s always sad on the inside?’’ Mr. Moore said in the WVUD interview. “So we wrote it.’’

The Miracles returned to the “Pagliacci’’ theme in 1970 with “The Tears of a Clown,’’ which has direct references to the opera.

Mr. Moore collaborated on hit songs with his Miracles partners for other Motown artists, including “Ain’t That Peculiar’’ and “I’ll Be Doggone’’ for Marvin Gaye.

Warren Thomas Moore was born in Detroit. His father, Odell, was a sculptor, and his mother, Oreatha, was a teacher.

Mr. Moore was 12 years old when he met Robinson, and by high school they were in a group called the Five Chimes (with White, a future Miracle) that won a contest on “Saturday Dance Party,’’ a Detroit television show. Mr. Moore said that moment let him visualize his future.

But at an audition in 1957 for Nat Tarnopol, R&B singer Jackie Wilson’s manager, the group, now rechristened the Matadors, was told it was not ready, Mr. Moore recalled. They were also told that with a female singer, Claudette Rogers, they sounded too much like the Platters. He suggested that they return in a year.

Disappointed, they left. But they were stopped outside by Gordy, who had listened to the audition, was impressed, and wanted to manage them. “We knew who he was,’’ Mr. Moore told WVUD. “Berry had written all of Jackie’s hits until then.’’

With Gordy as their manager — and with his help in improving Robinson’s songwriting — they changed their name to the Miracles and became an integral force at Motown.

Robinson last performed with the Miracles in 1972 before leaving to pursue a solo career and focus more on his role as a vice president of Motown. Mr. Moore remained with the Miracles until they dissolved in 1978. With Billy Griffin, who replaced Robinson as lead singer, he wrote “Love Machine (Part 1),’’ a No. 1 Billboard hit in 1976.

In addition to his wife, Mr. Moore leaves twin daughters, Monique and Monette, and a sister, Winifred.