Where are the go-go girls at the Boston Tea Party, the city's newest discotheque? They're up in the balcony behind powerful projectors, rocking little trays of oozing liquid in time with the live. On a distant screen, the highly magnified, undulating image sets the rhythm for the hundreds of melding figures below.

It all started when David Hahn, a former M.I.T. student, and Ronald R. Riepen, a student at the Law School, realized Boston was well behind the rest of the nation in high-quality discotheques. Their answer is the new "psychedelic discotheque" at 53 Berkeley St. Rather than attract a spectator crowd of teenie boppers, they have tried to "encourage an atmsophere of sophisticated participation."

They hope the Boston Tea Party will soon become "the spot" in Boston, and there are signs that this is already happening, scarcely more than a week after opening night.

The founders are still experimenting with unusual lighting effects. If you dance near one of the high frequency stroboscopic lights, your partner's smooth motion becomes a panorama of frozen positions superimposed on each other. Soon an IBM computer will be moved in to help control the blinking red and blue lights. And if you take your date over to a corner, about all you can see in the ultraviolet light is her glowing blouse and nail-polish.

But if you should merely want to stand by yourself without, participating, your best bet is to head for the empty five-foot semi-circle in front of one of the loud-speakers