Beginning at 11 a.m. inside Commonwealth Plaza, the Children's World Music Express, made up of performers Bill Koutsouros and Tammy Keorkunian, will engage children in a variety of songs, dances, styles, rhythms, and melodies from around the world.

The performing duo, whose show is targeted for children ages 5 and younger, will perform ethnic and American traditional songs with instruments from Greek, African, Indian, Latin, Middle Eastern, Western, and Asian cultures to entertain children and adults.

Bill and Tammy's Children's World Music Express is sponsored by PNC Grow Up Great, a 10-year, $100 million effort to prepare children from birth to age 5 for school and life. The PNC Grow Up Great series presents free performances for children in the Kimmel Center's Commonwealth Plaza the first Saturday of every month from October through May.

Online sleepover

The event, hosted online at www.beinggirl.com, will allow teen girls to play a truth-or-dare game and have a Q&A with the pop singer. The online party also will feature exclusive performances by Jordin, and expert tips for the perfect sleepover party, including recipes, hairstyling advice, games, and live chats. Girls must sign up on beinggirl.com to participate in the online sleepover.

For every girl who participates, the Sleepover sponsors - beinggirl.com and Always feminine-hygiene products - will donate $1 to Protecting Futures, a program by Always dedicated to helping girls in developing regions stay in school.

Concert series at Curtis

At 2 and 4 p.m., Curtis students will team up with kids in the audience for a one-hour session to demonstrate how to compose music and conduct an ensemble. The concerts, held in the Field Concert Hall at the Curtis Institute of Music, are suitable for children age 5 and older.

The family concerts are part of the Curtis Community Engagement Program, which shares classical music with young people and others in the local community who may not otherwise have access to the art form.