I respect Richard greatly as a producer, writer, arranger, musician, etc, but I think he was extremely wise to stop featuring himself as lead vocalist. Karen had a world-class voice. He had an average, singing-in-the-shower voice. But he did sound good when his vocals were blended with Karen's, in the background. They made good background vocals together - and Richard was smart enough to keep himself in the background vocal-wise from 1974 onwards.