Those lively Loesser songs!; Perfectly Frank Musical with music and lyrics by Frank Loesser and music by numerous other composers. Directed by Fritz Holt. Choreography by Tony Stevens.

Ten agile and accomplished performers, accompanied by a brassy pit band, sing and dance their way through the new musical entertainment at the Helen Hayes Theater. "Perfectly Frank," described on the marquee as "Frank Loesser Revued," utilizes a mere 65 of the 1,500 songs for which the prolific Loesser wrote the words or the words and music. His credits include more than 60 Hollywood films and five Broadway musicals.

This is a busy, often enjoyable, but too often overamplified musical. All the more welcome are the quieter numbers, including Jo Sullivan's performance of the unpublished "Central Park Duck," the comically poignant tribute to a Loesser feathered friend. More such quietude would have enhanced the charm of the retrospective.

But whether sassy and brassy or sophisticatedly classy, the show revels in the sound of music that marks Loesser as a versatile melodist with a liking for fugue and counterpoint and a flair for fascinating rhythms. Besides Miss Sullivan, the cast includes Andrea Ankers and Virginia Sandifur.

Just before the opening, the show underwent one of those backstage changes that make musical-comedy producers jumpy and keep press agents on their toes. Kenny Solms, originally credited with having conceived and written "Perfectly Frank," withdrew his name from the credits after director-choreographer Ron Field was brought in as an officially unidentified consultant to the production.

The chosen extracts from this voluminous output have been arranged into segments on various themes. After an overture and prologue, "Perfectly Frank" goes into its musical sampling. The first big production number, called "USO Show," remembers World War II, assembling tunes of the '30s and '40s. In the course of the medley, Jill Cook and Wayne Cilento jive to an all-drum percussion treatment of "Some Like It Hot"; Debbie Shapiro does a plaintive "I Don't Want to Walk Without You"; the whole company swings out with "Praise the Lord and Pass the Ammunition"; and Miss Sullivan takes the stage for a tenderly sung "Spring Will Be a Little Late This Year."

There are many other numbers in the show, which is credited to Fritz Holt as director with Tony Stevens responsible for the expertly performed razzle-dazzle choreography. John Falabella designed the casual costumes and gilt-arched setting, and Ken Billington lighted the production.