Talk to anyone involved with Elvis, and the word that always comes up in reverent tones is ''authentic.'' The creators of the new weekly ABC series, including co-executive producer Priscilla Presley, found an eerily perfect young-Elvis look-alike (Michael St. Gerard, who filled the same shoes in Great Balls of Fire) and are filming the series on location in Memphis, all the better to chronicle Presley's early career, beginning with the 1954 sessions at the Memphis Recording Service that changed both his liff and pop music. And like the scenery, the music seems real but it isn't.
When St. Gerard performs on stage or in a studio, what you are hearing are precise re-creations, recorded last fall in a Hollywood studio. ''Elvis is not here to sing the live stuff,'' says country singer and Presley sound-alike Ronnie McDowell, who is the singing voice of the King in the series. ''He's not here (in the studio) to do the half-verse, tits and pieces they need. They had to have somebody who's here now to make it real.''
The series' music director, Steve Tyrell, adds: ''It would be totally unrealistic to have him (St. Gerard) singing live to an Elvis record. If you play a record of Elvis', it doesn't have that spontaneity in it. It has its own spontaneity, but it doesn't have live-performance spontaneity.''
To attain that spontaneity and authenticity, Tyrell spent weeks renting antique guitars, microphones, and amplifiers from L.A. specialty shops all in an effort to duplicate the spare, echo-drenched hillbilly boogie achieved by producer Sam Phillips on the early Presley singles released on Sun Records. Technology in place, McDowell and two backup musicians (playing the guitar and bass parts of original Presley sidemen Scotty Moore and Bill Black, respectively) then cut 50 complete and partial tracks in a 32-track studio (31 more than Phillips had), even re-creating Presley's guitar-slapping technique. Also recorded were Presley-style versions of songs Elvis performed at the time but never recorded, such as ''Rock Around the Clock.'' ''We just get in there and become those cats,'' Tyrell says of the studio work. ''If at any time you don't believe the actor or you don't believe the music, then we've all failed and it's not going to work.'' Some original Presley recordings of the era are used, but only when a song is heard coming from a radio. ''Those records weren't perfect like we do 'em today, but they had so much feeling,'' McDowell says. ''Elvis at 19 was on fire. Can you imagine trying to re-create that? I had to think how he would do his mouth to get one word out or hiccup in a certain place.''
Neither man is a stranger to musical mimicry. Tyrell re-created big-band jazz for the soundtrack of the Baby Boom series and Cajun music for Frank's Place. (He also co-produced Linda Ronstadt and Aaron Neville's recent pillow-talk hit, ''Don't Know Much.'') McDowell first gained national recognition for ''The King Is Gone,'' a maudlin but heartfelt 1977 Elvis-tribute single that led to a semi-successful country career and jobs as a Presley sound-alike for the TV movies Elvis and Elvis and Me and this series.
Already there's talk of a soundtrack album of Presley recordings, McDowell remakes, and possibly a ''duet'' single (and video) teaming the real Presley and his imitator. In some otherworldly hemisphere, Elvis is making himself a peanut-butter-and-banana sandwich and wondering what a 32-track recorder is.