Bill put some soul & blues sound back in the band after Terry Kath's passing. Once Cetera left and was replaced by Scheff, I don't think they were ever able to do it "live" as with Peter. Cetera is one of those top 5 singers (per Foster) that could and can do a perfect performance every night. Scheff is no slouch, and can do a fine job in the studio, but check some of the videos of the two lineups, his live performances lack the control and power of Cetera. I think Bill is the most consistent singer the band has (live). Back in the day, he, Kimball and McDonald were the power trio who sung backup for everybody. His association with Foster and Graydon is also quite the feather. Anybody know if Foster is the one who recommended him for the band to replace Kath's vocals? Would seem to make sense that he was on the "short list" as Foster was producing at the time, and I saw them all on Thicke of the Night (Airplay lineup) video right around the time he joined the band.