City Councilman Michael A. Sullivan has asked Cambridge Chief of Police Timothy Leahy to investigate and, if necessary, prosecute the backers of the musical play "The Cradle Will Rock," which was produced by the Student Union on Saturday, May 27, in Sanders Theatre, he announced last night.

This move follows an attack he made at the City Council's meeting on Tuesday on Harvard "Reds" whom he also linked with the Memorial Day rites incident when fighting between students and "townies" occurred.

At this meeting he offered to play phonograph transcriptions of the play to the Council in order to prove that the play was "indecent," but his offer was rejected by Council President Thomas N. McNamara.

Claims Ordinance Applies

The action is based on a city ordinance requiring that a police permit be obtained for performances open to the public, Sullivan said. As far as could be learned yesterday this rule has never before been invoked on shows produced on University property.

Sullivan, known to students and citizens as "Mickey the Dude," is councilman for the district which includes Harvard.

Learning of Sullivan's statement last night, David W. Prall, associate professor of Philosophy, and one of the Faculty sponsors of the production, defended "The Cradle Will Rock" as having "the purity of actual brilliance compared with ordinary burlesque shows and cheap movies."

" "The Cradle Will Rock' was presented by a Harvard student organization in one of Harvard's own buildings and not for the benefit of any outside organization," Prall said.

"The critics both in New York and Boston have praised it as 'interesting', 'important', 'vital', and 'original', particularly as a musical score. The Harvard performance was sponsored by a Faculty Committee who have a reasonable amount of critical competence.

"Several of them have served as advisers for Harvard Dramatic Club plays in which the Dean of Radcliffe has allowed students to take part. Mr. Sullivan may be a better judge of the tone of the play than Mr. MacLeish, but in any case the question is just what Mr. Sullivan means by indecent.

"Perhaps he was so deaf to the actual quality of the performance that his charge rests merely on the occurrence of 'them big words' that Larry's Aunt Jessie found in her Bible, in the play'"