FRIDAY: >> The Millennium Stage Conservatory Project concludes this weekend at the Kennedy Center. Promising young musicians from the nation’s best conservatories will be giving free concerts in the Terrace Theater: Eastman School of Music (tonight), Jacobs School of Music, Indiana University (Saturday), and Shepherd School of Music, Rice University (Sunday). All concerts begin at 6 p.m. and can also be experienced by live simulcast through the Millennium Stage Web site. >> Garrison Keillor brings…