Sears broadcast test transmissions from its own studios on April 9, 10 and 11, 1924, using the call sign WES (for "World's Economy Store"). Sears originally operated its station at the company's corporate headquarters on Chicago's West Side, which is also where the company's mail order business was located. On April 12, 1924, the station commenced officially, using the call letters WLS (for "World's Largest Store"), and broadcasting from its new studios in the Sherman House Hotel in downtown Chicago. The station's transmitter was originally located outside of Crete, Illinois. On April 19, the station aired its first "National Barn Dance". Harriet Lee was a WLS staff singer as part of the "Harmony Team" in the late 1920s. The popular contralto singer also played "Aunt May" on the "Children's Hour" show. The station shared time on the frequency with WCBD until November 11, 1928, at which point it began sharing time with WENR.