Saroyan novel becomes charming pop opera; The Human Comedy. Musical adapted from the William Saroyan novel by composer Galt MacDermot and librettist William Dumaresq. Directed by Wilford Leach.

Goodwill and good feeling, tenderness, and affection create the warmth that radiates from ''The Human Comedy,'' at the Public/Anspacher Theater.cq Galt MacDermot and William Dumaresqcq have distilled William Saroyan's bittersweet 1943 novel into a pop opera of exceptional charm and winning appeal. The sense of embrace that begins by flanking the numerous cast with two sections of a small orchestra extends figuratively to the feeling of shared joy and wonder that enfolds the audience.

''The Human Comedy'' is set in mythical Ithaca, Calif., in the early days of World War II. Fourteen-year-old Homer Macauley (Stephen Geoffreys) has just gone to work as a messenger boy at the local Postal Telegraph office. Besides Homer, the Macauleys include little wandering Ulysses (Josh Blake), wisely maternal widow Macauley (Bonnie Koloc), pretty sister Bess (Mary Elizabeth Mastrantonio), and GI brother Marcus (Don Kehr), who is off to the war from which he will not return. Homer quickly wins the approval of Spangler (Rex Smith), the good-natured Postal Telegraph manager, and Mr. Grogan (Gordon Connell), the tippling but otherwise reliable old telegrapher.

Like ''Our Town,'' which it resembles in some ways, ''The Human Comedy'' concerns life and death and growing up in a small community. Death reaches Ithaca mainly via the official telegrams Homer delivers to the families of soldiers killed in action. The strain of bearing such tidings creates the lad's inner conflict as he reaches for the maturity he will need to become ''man of the family'' when word of Marcus's loss comes clacking over the telegraph receiver.

In its musical form, ''The Human Comedy'' adapts the loving vignettes of Saroyan's novel to the operatic needs of aria, recitative, and vocal ensemble. Along with its poignancy and heartfelt feeling for home, the adaptation captures Saroyan's joie de vivre.

The adapters have provided a generous mix of musical idioms and rhythms: Love songs, jazzy upbeat numbers, a gospel hymn, and a variety of other compositions in the MacDermot manner. The moods range from jubilation to quiet reverie. The rewards for the listener are rich and sometimes surprising. Tania Leon conducts the MacDermot orchestrations with the kind of authority and dedication that make for listening pleasure. Besides those mentioned, the fine cast at the Anspacher includes Delores Hall, Joe Kolinski, Caroline Petyon, Leata Galloway, and David Johnson.

The performance flows from scene to scene under Wilford Leach's direction. The stage is bare save for a few occasional chairs and a telegrapher's desk. Rita Ryack's good period costumes and Stephen Strawbridge's responsive lighting compose the sparse production's only other physical embellishments. Thanks to the devotion and skill with which the lovely adaptation is performed, there's nothing sparse about the warm humanity of ''The Human Comedy.''