This Saturday, Harvard Square will host a mini-festival of arts-related demonstrations, performances, and workshops, all presented under the aegis of "Contemporary Arts Day," a joint project of the American Repertory Theatre, the Institute for Contemporary. Boston Musica Viva and Dance Umbrella. These are the cream of local arts institutions, and between them they cover virtually every medium, so there should be something to please every taste.

Here is a quick guide to some highlights of the day. The events listed here will all take place at the A.R.T., 64 Brattle Street.

11 a.m.: LINES IN THE SAND.

Composers including Michael Gandolfi, professor of Music 2, will discuss the various schools of composition today.

11:30 a.m.: INSIDE THE VISIBLE.

Screening of a documentary about the impact of women artists on 20th century art; includes interviews with artists such as Louise Bourgeois and Nancy Spero.

2:15 p.m.: "DOING" MAMET.

Scott Zigler, who will direct the world premiere of David Mamet's The Old Neighborhood at the A.R.T. this year, will present an open rehearsal of a scene from the play, followed by a discussion.

4 p.m.: CREATION.

Choreographers Amy Spencer and Richard Colton will create a piece with the first 15 people who sign up.