Malik Taylor, the rap artist known as Phife Dawg who was a founding member of the pioneering group A Tribe Called Quest and who helped bring new elements of social awareness and musical sophistication to the hip-hop form in the 1990s, died March 22 in Oakley, Calif. He was 45.

The cause was complications from diabetes, his family told the Associated Press.

Mr. Taylor joined Q-Tip (born Jonathan Davis), a childhood friend from Queens, to form A Tribe Called Quest in the late 1980s. They were the group’s complementary and competitive emcees, or principal onstage presences, and were supported by the group’s two other original members, DJ Ali Shaheed Muhammad and Jarobi White.

Mr. Taylor, who was generally known to his fans as “Phife” or occasionally the “Five-Foot Assassin” for his diminutive size, provided a high-pitched, keening vocal contrast to the smoother style of Q-Tip. He announced his presence in 1991’s “Buggin’ Out”:

Hip-hop performer Malik "Phife Dawg" Taylor has died at the age of 45. Taylor was one of the founding members of the group "A Tribe called Quest," and was diagnosed with diabetes in 1990. (Erin Patrick O'Connor/The Washington Post)

Yo, microphone check one two what is this

The five foot assassin with the ruffneck business

I float like gravity, never had a cavity

Got more rhymes than the Winans got family

A Tribe Called Quest produced five albums from 1990 to 1998, becoming one of hip-hop’s most popular groups. The quartet’s top-selling hit singles included “Can I Kick It?,” “Check the Rhime,” “Jazz (We’ve Got),” “Award Tour” and “Bonita Applebum.”

Tribe, as the group’s fans often called the group, was considered a seminal influence on such later stars such as Kanye West, the Roots and Common.

“A Tribe Called Quest was like nothing I had ever heard,” Roots and “Tonight Show” drummer Questlove wrote last year in Billboard magazine. “It was stylish, funny, jazzy, soulful, smart and everything else. Tribe was socially conscious without being too self-conscious about it.”

Malik Taylor, rapper known as Phife Dawg of A Tribe Called Quest, in 2011. (Andrew H. Walker)

Among other things, Tribe introduced a sense of playfulness, irony and social awareness to its music, in contrast to much of the violent and misogynistic posturing then popular in hip-hop.

“A Tribe Called Quest is not talking about your average gangsta,” Mr. Taylor told the Boston Globe in 1994. “That’s just not what we do.”

The group’s lyrics, written largely by Q-Tip and Mr. Taylor, addressed such sensitive topics as date rape, religious faith, human rights, police harassment and use of the n-word by African American youths. Mr. Taylor touched on several weighty subjects in just a few lines of “We Can Get Down,” from the 1993 album “Midnight Marauders.”

How can a reverend preach, when a rev can’t define

The music of our youth from 1979

We rap about what we see, meaning reality

From people bustin’ caps and like Mandela being free

Not every MC be with the negativity

We have a slew of rappers pushin’ positivity

The relationship between Mr. Taylor and Q-Tip turned fractious over time and helped contribute to the group’s breakup in 1998. Both artists embarked on solo careers, but the charismatic Q-Tip found much greater success. Mr. Taylor took a snarling swipe at him in his 2000 single “Flawless.”

“I always sort of liked the analogy of them being like the Rolling Stones,” Michael Rapaport, who made a documentary about the group, told the New York Times in 2011, “Q-Tip being Mick Jagger and Phife being Keith Richards.”

Malik Isaac Taylor was born Nov. 20, 1970, in Queens and was close friends with Q-Tip (whose full name is now Kamaal Ibn John Fareed) from age 2.

By their mid-teens, the two were rhyming together and formed an early version of A Tribe Called Quest.

Their first album, “People’s Instinctive Travels and the Paths of Rhythm,” appeared in 1990, followed by “The Low End Theory” in 1991 and “Midnight Marauders” in 1993. (“Marauders” went platinum in 1995.)

Two other albums, “Beats, Rhymes and Life” and “The Love Movement,” were released in 1996 and 1998, respectively.

In addition to socially conscious lyrics, A Tribe Called Quest was known for its innovative musical approach, including the layering of rhythms and its wide-ranging sampling from jazz and other forms of music.

Snippets of music from Cannonball Adderley, Little Feat, Grover Washington Jr., the Average White Band and countless other sources can be heard under the lyrics of Q-Tip and Mr. Taylor.

“We were all being labeled as bohemian rap, jazz fusion and all kinds of things,” Mr. Taylor told the Hono­lulu Star-Bulletin in 2001, “but it’s not that we were trying to be different from everyone else; we were just trying to be ourselves.”

In the 1990s, A Tribe Called Quest became linked with a group of culturally aware East Coast hip-hop artists, including De La Soul, Jungle Brothers, Monie Love and Queen Latifah. The loose collective known as the Native Tongues extended the aesthetic and intellectual boundaries of the genre.

Mr. Taylor struggled with diabetes for more than 20 years and received a kidney transplant from his wife in 2008.

Last year, he said he was in need of a second kidney transplant.

Complete information about survivors was not immediately available.

Mr. Taylor moved to Atlanta in 1994 and later to California.

A Tribe Called Quest had occasional reunion performances over the years, most recently on Jimmy Fallon’s “Tonight Show” in November.

The group re-released its debut album last year, with some tracks remixed by Pharrell Williams, CeeLo Green and J. Cole.

Rapaport’s 2011 documentary, “Beats, Rhymes & Life: The Travels of A Tribe Called Quest,” delved into the bitter breakup of the group’s two lead performers, and Mr. Taylor was said to be in tears while watching the premiere.

“Back in ’89, I simply slid into place,” Mr. Taylor rapped in the 1993 song “Award Tour.” “Buddy, buddy, buddy all up in your face. A lot of kids was busting rhymes, but they had no taste. Some said Quest was wack, but now is that the case?”