From April 20 to May 1, Boston’s WCRB radio station is broadcasting a music festival entitled Festival 1750, featuring previously recorded performances by Boston Baroque, the Handel and Haydn Society, and the Boston Early Music Festival. WCRB host and producer Alan McLellan will host Festival 1750, which features works written immediately before and after 1750, the rough diving line between the Baroque and Classical periods. Concerts will be broadcast in the Boston metro area at 99.5 FM each weekday at 9 p.m. and online at www.classicalwcrb.org for two weeks starting on April 20. Festival highlights include the Handel and Haydn Society’s performance of Beethoven’s Fifth Symphony; Boston Baroque in concertos by Vivaldi and Telemann; and the Boston Early Music Festival Orchestra in selections from Rameau operas. The series will culminate on May 1 with a program featuring performances from all three organizations. Visit WCRB’s website for more information and a complete schedule.