Lil Peep, who over the last two years emerged as one of pop music’s brightest and most promising young talents, blending the urgency and dexterity of contemporary hip-hop with the raw, serrated sentimentality of emo, died on Wednesday night in Tucson. He was 21.

Sarah Stennett, the chief executive of First Access Entertainment, a company that worked with Lil Peep since last year, confirmed the death in a statement. Ms. Stennett said she had “spoken to his mother and she asked me to convey that she is very, very proud of him and everything he was able to achieve in his short life.”

A spokesman for the Tucson Police Department said Lil Peep was pronounced dead on his tour bus at approximately 9 p.m. He had been scheduled to perform at a club called the Rock. Detectives found evidence suggesting that the rapper died of an overdose of the anti-anxiety medication Xanax.

Lil Peep was born Gustav Ahr on Nov. 1, 1996, and was raised in Long Beach, on Long Island, the son of a college professor father and an elementary schoolteacher mother. He took his name from a childhood nickname given by his mother.