* Chorus concert. Fine and Performing Arts Center Theatre, Catonsville Community College. 8 p.m. 455-4590. Free.
* 116th running of the Preakness Stakes. Middle jewel of thoroughbred racing's Triple Crown. Pimlico Race Course. Gates open at 8:30 a.m.; first post time 11:30 a.m. Daylong infield party with live music, prize giveaways. 542-9400. Admission.
* Eighth annual bluefish tournament on the Chesapeake Bay. 7 a.m.-4:30 p.m. More than $225,000 in cash and prizes. (301) 768-8666. Entry fee.
* Antique Aircraft Fly-In. Horns Point Aerodrome, Dorchester County. 9 a.m.-5 p.m. (301) 228-1899. Free.
* 2-for-1 Day at Hammond Har
wood House. Annapolis. 10 a.m.-5 p.m. 18th century historic house. (301) 369-1714. Pay one admission-get one free.
Laurel's Main Street Festival and Parade. Laurel. 10 a.m.-5 p.m. (301) 725-1234. Free.
* Springfest. Chesapeake Bay Maritime Museum, St. Michaels. 10 a.m.-5 p.m. (301) 745-9235. Admission.
* Chesapeake Hobie Cat Fleet 54 Sailboat Regatta. Gunpowder Falls State Park, Chase. 10 a.m.-6 p.m. (301) 433-4042. Free.
* Dundalk-Eastfield Italian Festival. Dundalk Heritage Park. Noon-10 p.m. 887-7155. Admission.
* Preakness Celebration Lunchtime Concert. Harborplace amphitheater. Noon-1 p.m. Gene Walker Orchestra's big band jazz and contemporary music. 332-4191. Free.