DEBORAH DAVIS strode happily to the microphone at Carlos 1 the other evening, like a bettor on her way to the cashier's window. After a year-long struggle at marginal engagements in New York City, Davis was on a major stage, and in the company of a classic jazz figure, Clark Terry.

The engagement at Carlos 1, 432 Sixth Ave. near 10th Street, belongs to Terry, who has often lent his towering presence on trumpet and flugel in support of talented performers who deserve higher visibility. Besides Davis, Terry is surrounded through Sunday evening ($10 music charge, $7 minimum) by players who have distinguished themselves before with the leader: pianist Charles Fox, bassist Marcus McLaurine and drummer Charles Braugham.