Mr. Herman's fame is so closely allied with the better-known songs from ''Hello, Dolly!'' and ''Mame'' that most of his other work is virtually unknown. And, as ''Jerry's Girls'' reveals, there is a marvelous catalogue of songs waiting for the kind of exposure they get here. Because Mr. Herman's favorite score is ''Mack and Mabel,'' it is not surprising that there are more songs in ''Jerry's Girls'' from that short-lived production than any of his other shows. They justify Mr. Herman's affection for them and, along with the other songs, they are given the velvet setting that pearls deserve in Larry Alford's imaginative staging.

 Even ''Hello Dolly!,'' a triumph of staging in its time, becomes a new triumph when Mr. Alford surrounds his four singers with life-size cutouts of Mr. Herman dressed as a waiter as they recall some of the stars who have sung it, some of the languages it has been sung in, its commercial use as a tribute to hamburgers (''Hello, Hardees!'') and its political incarnation as ''Hello, Lyndon!''