Don't know about 'worst song' or 'respectable artist' but the SILLIEST song I ever heard was 'The Man who Called Himself Jesus' by (I think) Dave Cousins of the Strawbs. What used to get me is that everyone around me seem to treat this ludicrous travesty with great seriousness; they didn't even smirk at the silliest line of all which went something like, 'he thought his pint of beer had turned into a pint of blood' - yuckkkk!!!