The African Children’s Choir joins Tom in Studio A to preview their concert tonight in Baltimore. These 18 young singers, aged between 7 and 10 years, are all from Uganda. They are on a 9-month, nearly 50-concert tour of the United States. After Baltimore, they'll venture across the mid-Atlantic, up to New England and then out west to Arizona, Colorado, New Mexico and Utah.Over the years, the African Children's Choir has performed for heads of state and shared the stage with celebrated artists such as Paul McCartney, Mariah Carey and others.Tonight, at 7 pm, they will be performing n Baltimore at St. Matthew Catholic Church at 5401 Loch Raven Blvd. The concert is free and open to all. Donations are welcome as they support African Children's Choir programs such as education, care and relief campaigns.