Some people are not good at all things, or Jimmy Webb is not a good singerby Commander Tansin A. Darcos 10/30/2015, 9:53am PDT
Jimmy Webb is one of our generation's most talented composers (Up, Up and Away, Wichita Lineman, etc.) and is a reasonably good piano player. However, he never managed to have a career as a singer as some other well-known performer-composers such as Neil Diamond, Paul Simon, Peter Cetera, Don Henley and many others.
The fact is, he's terrible at it! I noticed it when he performed what is probably his most famous composition, McArthur Park. He's off key, which you would think is strange for a musician, that he apparently doesn't know what his own register (range of vocal notes) is. If you want to sing a song properly it has to be within your register, otherwise you get some obscene horrors like Roseane Barr singing the National Anthem, badly. (It doesn't help that the Star Spangled Banner is not an easy song to master.) Now you compare that to the time that Whitney Houston did it and it sounded like an angelic choir.
So the fact remains that Webb, as talented as a composer and musician, is either a not very good singer or has not properly trained to be one.
But don't take my word for it; hear his performance yourself. Here's two three versions of McArthur Park, one with Jimmy Webb performing his own composition back in 1971, and a recent performance with him on keyboard (only) done on the David Letterman show.
Jimmy Webb, from 1971:
(The comment on this one by the uploader summarizes it exactly, "Paul Schaefer, Jimmy Webb and the CBS Orchestra blow the roof off with this performance.")
There is, of course, the original by Richard Harris from 1968: (Note the version by Harris is 7:28, the one done on Letterman's show is the same full performance but is 2 minutes shorter).