Fiorello! is pretty appropriate for election week, being a musical about New York's great Depression-era mayor, Fiorello H. LaGuardia. LaGuardia, it was said, with an Italian father and a Jewish mother, was a balanced ticket in himself; he was so popular he said of the party hacks "I could run on a laundry ticket and beat those political bums." He loved little children and the Fire Department and is chiefly remembered, in New York, for reading the funnies over the radio during a newspaper strike. But the musical isn't nearly as colorful or interesting as the man himself. At Agassiz Theatre tonight, tomorrow and Saturday at 8 p.m. Tickets $2.

Calm Down Mother and Comings and Goings by Megan Terry, and dramatic readings from the poetry of the late Anne Sexton, presents some of the work of two talented, intriguing contemporary woman writers. Not all the writing is feminist. Most of it's quite good. At the Ex tonight, tomorrow and Saturday at 8 p.m.

Philadelphia, Here I Come dramatizes the thoughts of a present-day Irish immigrant just before he leaves for the United States. The play itself, by Brian Friel, offers a number of insights into the situation of introverted young men in traditional societies, but unfortunately it's performed in the round and it's not always easy to see what's going on. At Leverett House Old Library tonight, tomorrow and Saturday at 8 p.m. Tickets $2.

Bye Bye Birdie, a classic musical comedy about teenage life in the '50s, is about Conrad Birdie, an Elvis Presley figure who decides to kiss one girl goodbye on national television before being drafted. Some of the songs, like "Going Steady" and "Kids," are classics, and the grand climax--on the Ed Sullivan show--is a knockout. At Mather House tonight, tomorrow, Saturday, and Sunday at 8:15 p.m. Tickets $2.

Dracula is a play about the 14th century feudal chieftain known for nailing hats into the skulls of people who refused to remove them in his presence. The play itself, when presented at the Loeb last spring, was pretty awful, but Boston being the center of Dracula studies that it is--the world's two leading authorities teach at B.U.--maybe it'll turn out better at the Theater 369. Performances nightly (except Monday) at 8. Info: 628-1266.

Lenny really gets into the spirit of St. Bruce, the Martyr, but it's hard to see how the abysmal TV comedian Marty Brill can pull it off; so this remains a good bet only fro enthusiasts. Charles Playhouse, Tues.-Fri. at 8 p.m. Saturday, 6 and 9:30 p.m., Sunday at 3 and 7:30 p.m.