But I have to say I don't think Tesh is as bad, because I think with the John Tesh show, the music is selected locally by the radio station, while Delilah has her own playlist.
Not entirely. Tesh does use his own playlist, but there's a customized version that stations can use to drop in their own music. Mix 98.7 here in Jackson does this now since they moved him to middays. When they aired him at night, they went with whatever he played.