MUSIC REVIEW : S.D. Singer Displays Star Quality Live : Country: Opening for Restless Heart, Calman Hart won over the noisy Sound FX crowd.

When a recording artist faces a live audience for the first time, he earns validation on the basis of two criteria: whether his musical chops are sufficient to sustain his material outside the laboratory conditions of the recording studio, and whether the intangibles that give his music its soul translate well to the stage. At Sound FX on Thursday night, San Diego country singer-songwriter Calman Hart passed both tests with room to spare.

Hart isn’t well-known (yet), but he qualifies as a recording artist on technical grounds because he released an independently produced CD, “Red-Eyed & Blue,” earlier this year, and, aesthetically, because the album showcased professional-caliber writing and performing talents. Although he’s played the occasional set at area clubs, Hart considered this chance to open for big-selling country-pop band, Restless Heart, his official debut.

Hart--a systems analyst for a local law firm--had the formidable task of winning over a noisy crowd of several hundred that had come to hear the headliner. Playing amplified acoustic guitar with a deftness that betrayed his classical training on the instrument, and ably accompanied by guitarist-vocalist Jim Groutage (with whom Hart co-produced “Red-Eyed & Blue”) and vocalist Delene St. Clair, the Utah transplant cleared his first major hurdle early in what would be a 40-minute, semi-acoustic set.

Hart began with the country-folk tune “Red-Eyed & Blue,” whose loping tempo and ear-snagging refrain (“At the Hotel America, home of the lonely, red-eyed and blue”) easily captured people’s attention. But he took a risk by following with the album’s “Slow Down (The Horses Are Dying),” a moody, downbeat ballad about the breakup of Hart’s marriage.

The first few bars of the song were drowned out by pockets of rude revelers intent on continuing their party-at-any-cost socializing. But, by the second verse, the club had quieted. After the song’s last line--”Slow down, the horses are dying, you’re driving them into the grave”--the place erupted in spontaneous applause and cheers.

Most performers would hitch their show to such an upswing in momentum by singing an upbeat crowd-pleaser. Hart, however, raised the stakes with a solo rendition of a ballad, “Seeing You Go,” that isn’t even on his CD. Like his early idol, James Taylor, Hart sings in an appealing, unpretentious baritone that soft-sells the relatively dark emotional content in his lyrics. During the sad ballad, which joins a pretty, pop-angular melody to folk-simple chording, one could have heard one’s hair growing.

By the fourth song, a duet with St. Clair on the CD’s lilting, mid-tempo country ballad, “Break My Heart Gently,” the crowd was sold on Hart, who closed the deal with the kind of natural amiability that many performers achieve only after years on the boards.

“This next song is about someone I used to know who was, well, something of a crocodile,” a grinning Hart said in introducing “It Don’t Hurt Me None.” Placed this far into the set, the up-tempo strut was less a mechanical pacing device than an assured demonstration of Hart’s lighter nature. Although it closed the first part of his performance, the toe-tapper was a set-up for the song he would perform after a brief solo interlude by Groutage.

“That short break gave me a chance to change into my new boots for this next song,” Hart said upon his return from backstage, raising a leg to exhibit a pair of red-suede clod-kickers. “Honey, Don’t Scuff These Boots”--a brisk two-step inspired by Hart’s trek across New York’s Central Park after a day of boot-shopping--found a responsive nerve in the country-clad crowd, which hooted for half a minute at its conclusion.

With his CD (on sale at Tower records), Hart proved that he has the talent to compete with the big boys in the contemporary country field. Thursday night, he exhibited the skills, the presence, and the personability necessary to take his case to prospective fans. Hart recently returned from an exploratory trip to Nashville. If a major label there doesn’t snap him up, then logic does not rule Music City.

For their part, Restless Heart comported themselves with the style one would expect from hit-making professionals. But, at several points, the group displayed the uncertainty of a band in transition. Shortly before the release last January of their greatest-hits album, popular lead vocalist Larry Stewart left Restless Heart to pursue a solo career. It was obvious Thursday night that the remaining foursome is striving to create a new identity.

The first hint of nervousness came when keyboardist Dave Innis addressed the Sound FX crowd with a loud, “Welcome to the Bacchanal!” Oops.

Later, bassist Paul Greg fished for approval by asking the crowd how they liked the current band. These guys sounded and looked a little worried, and although Thursday’s audience seemed to enjoy their show, the new Restless Heart faces a crucial test with the release of their next album (due in late summer or early fall).

If their performance was an indication, these guys needn’t be so concerned. Innis and guitarist Greg Jennings have chops to burn. Their four-part harmonies are flawless, and their new material--which shows the band moving even more in a pop-rock direction--is strong. But it couldn’t have eased the musicians’ fears that, predictably, their older songs earned the best response.

Such selections as “I’ve Never Been So Sure” (from the 1990 album, “Fast Moving Train”), “The Bluest Eyes in Texas” (from 1988’s “Big Dreams in a Small Town”), and, of course, the gorgeous ballad “I’ll Still Be Loving You” (from 1986’s “Wheels”) brought the fans to their feet, and their feet to the dance floor. It should nonetheless encourage the band that several cuts from the next opus elicited enthusiastic response.

Meanwhile, there seems to be a bit of a tug of war between Greg and Innis to see who will be the dominant vocalist in Stewart’s absence. Greg demonstrated that he has the stronger voice, while Innis has more stage personality. Perhaps it won’t matter who wins. Restless Heart’s very solid showing Thursday night suggested that, if they can sort everything out in time, they should remain a presence on the contemporary country charts without a loss of valuable momentum.