CEDAR RAPIDS — A dream became a reality this week as a new Cedar Rapids-based chorus debuted to the public during its first concert.The group performed its first concert to a crowd of about 150 at Mercy Medical Center Monday, performing songs reminiscent of another era such as “Yellow Submarine” and “Oh Shenandoah.”The chorus, called Together in Song, is made up of individuals living with chronic conditions — including dementia, cancer and other conditions — as well as their caregivers and volunteers.