To sing as a round , one singer ( or group of singers ) would begin at the beginning , a second singer would start at the beginning as the first got to the point marked with the red cross , then the third would join in when the second singer got to the red cross , and so on until all six were singing . To sing as a round , one singer would begin at the beginning , and a second would start at the beginning as the first got to the point marked with the red cross .