Baryshnikov will dance, and Dean Martin will sing. Don Rickles will tell a few jokes, and Tom Selleck will probably just stand around being, oh you know -- Tom Selleck. But most notable may be the fact that the Beach Boys and Wayne Newton -- the singers over which there was a public squabble two July 4ths ago -- are both invited to perform at the inaugural galas.

Ronald Reagan's inaugural committee yesterday announced the entertainers who will perform at the January 18th and 19th galas at the D. C. Convention Center, in honor of the vice presidential and presidential inaugurations, respectively. Ticket prices range from $150 for a single seat to $10,000 for a box.

The list was compiled, according to the galas' chairman Joe Canzeri, by Nancy Reagan, Frank Sinatra, the galas' honorary chair, and Michael Deaver, the inaugural general chairman.

In making the New Year's Eve announcement, Deaver's statement said: "We were certain that reporters would have nothing so much on their minds as evening entertainment."

Sinatra, performing in Las Vegas, could not be reached for comment.

Included on the list are several longtime friends of the Reagans, such as Charlton Heston, Jimmy Stewart, Efrem Zimbalist Jr. and Sinatra, who is still remembered for his 1981 gala rendition of "Nancy with the Laughing Face."

Others who will perform at one or both of the events are Ray Charles, Mac Davis, the Gatlin Brothers, Rich Little, Dean Martin, Elizabeth Taylor and Tony Randall. It was unclear whether Newton and the Beach Boys would perform on the same night. Little, Stewart and Heston also performed in the gala celebrating Reagan's first inaugural.

"The whole concept was to generate a feeling of America," said Canzeri. "There will be cohosts and performers. We're still working out the format . . . What you've got here is some comedy, some country-western, and some well-regarded American performers."

Canzeri said that the film and stage stars such as Selleck, Heston, Taylor and Randall, will probably serve as the cohosts or do dramatic readings. Four years ago, for instance, Heston read a series of quotes by American writers.

This year's events will be for a somewhat smaller audience than the last, which was held at the larger Capital Centre. Instead of 18,000 spectators, about 12,500 are expected on each of the two nights. Among other things, the scaling down of the guest list is expected to help with the traffic flow -- but make tickets considerably more valuable.

Both shows will be filmed and portions shown Jan. 19 on ABC-TV.

Reagan's 1981 inaugural came under some criticism for its conspicuous glitz and overwhelming costs. This time, the inaugural committee has gone to great lengths to play down the activities.