OLD ROCK, NEW LIFE

WHEN A.B. QUINTANILLA talks about his sister Selena, the Tex-Mex music star murdered last March, allegedly by the former president of her fan club, his voice breaks with emotion. "I produced all of Selena's Latin stuff, all her successful stuff, and I'll never run into a vocalist like her ever again, or have a sister like her," he says. "That's what gives me an empty feeling--losing her first as a sister and then as a vocalist."

But we haven't lost her as a vocalist. On July 18, EMI Records will release Dreaming of You, a half English, half Spanish pop album that was completed after Selena's death. The CD will undoubtedly bring her music to a far wider audience than she ever had when she was alive. That should not be surprising. The music world has long been fascinated with performers cut off in their prime; death, the old saying goes, is frequently a good career move.

Today, advances in recording technology have given record producers an even greater ability to finish up the work of deceased performers, to remix, remaster and rejigger unfinished recordings with digital precision, and, via aggressive '90s marketing, to sell them to the public as authentic. In December, EMI will issue a Beatles boxed set with several new tunes, at least one featuring the voice of John Lennon, who died in 1980. Previously unreleased tracks of Lennon's singing are being combined with newly recorded vocals from the three surviving Beatles. On one cut of Selena's new album, her Spanish vocals have been lifted from a song released years earlier and mixed with new English-language vocals by the group Barrio Boyzz. Meanwhile, a posthumous "new" album by Jimi Hendrix, Voodoo Soup (MCA), recently arrived in stores. It features Hendrix, the guitar genius who died in 1970, jamming with freshly recorded drumming by Bruce Gary, a former member of the defunct '70s band the Knack. Would he have been Jimi's first choice? Some fans say no, but the dead can't pick sidemen.

Posthumous albums can mean big money. The grunge band Nirvana sold more than 7 million copies of its Unplugged CD, released after the group's lead singer, Kurt Cobain, committed suicide last year. Selena's Spanish-language albums have sold 2.5 million copies since her death. Then there's the inevitable merchandising. The new retrospective album of reggae great Bob Marley, Natural Mystic, contains three full pages in the liner notes plugging "Bob Marley Official Merchandise," such as T shirts and knit caps. And continuing enthusiasm for Hendrix--he sold 3.5 million albums last year--has spawned a virtual cottage industry. A documentary about the guitarist by filmmaker D.A. Pennebaker is currently in the works; an interactive Hendrix kiosk is on tour; and a $60 million Jimi Hendrix Museum is under construction in Seattle.

Posthumous popularity, however, can lead to conflicts, both financial and artistic. Hendrix's father Al is suing Jim's former lawyer, Leo Branton Jr., and Hendrix acquaintance Alan Douglas, claiming he was duped into selling them the rights to his son's music and image. Douglas, who has produced many of Hendrix's posthumously released records, contends it was his business sense and creative choices that made the Hendrix legacy so profitable in the first place. "It's been a long, difficult trip to revive Hendrix," he says. "But I'd say we have in fact rescued him, and he's selling more than he ever did."