My roundabout way of explanation is that people who earn "A"'s and "F"'s know it; most of the time you are documenting objective deficiencies or problems or moving from highlighting specific examples of excellence rather than giving generic or vague praise.
Writers who earn "D's" generally are just happy they didn't fail, while writers who earn "B"'s may be disappointed they didn't get an "A" but may not have had the expectation that they would.
The thing about a "C+" or "B-" is that you are saying, as an evaluator that the work is better than average. You are pointing out successful attributes of the work. Doing so inevitably leads to the question, "Well, then why wasn't the assessment higher?" So you then have to turn around and point out the weaknesses or flaws as well.
It is this requirement to point out both--strengths and weakness--that make grading such works so tricky. In other works you may just have to point out one or the other.
I have 46 "C" songs in my Ipod. (48 actually, but I only counted once for two songs by Sting for which I had two versions--from studio and live album--"Children's Crusade" and "Consider Me Gone.') In ranking them from 1 to 46, I figured the songs ranked 18-23 would be the equivalent of my C+ "C" songs. (Boy, isn't that awkward to type?)
"Corey's Coming" -- Harry Chapin.
Chapin is a story-teller, so as a whole you might like or dislike his work depending on whether or not you like ballads. Like most ballads, this one can move me when the story reaches its climax, and it is there that Chapin's lyrics get the most power via simple directness rather than bombast. ("So I said if you're a relative, he had a peaceful end/That's when she said, "My name is...Corey.../You could say I'm just a friend." On the downside, though, the chorus of this song makes no sense. ("Like I told you/when she holds you/she enfolds you/in her world.") In fact, the chorus suggests that Corey has somehow drawn John Jacob into her world rather than inspiring and sustaining him to survive in his own.
"Christians and the Pagans" -- Dar Williams
I like Dar Williams a lot, but this song lacks some of the ambiguity of Williams's better work ("Teen For God," and "I'll Miss You Till I Meet You" for example). There is a contrast in the lyrics of "CATP" but maybe not the internal conflict borne out of self-questioning and probing leading to a more mature, developed faith. Actually this is true of "Beautiful Enemy" as well, a song I love. It's like the more self-assured the speaker in the song is of the rightness of her position, the less interesting or complex the song is. While there are hints of dawning self-awareness in "Beautiful Enemy" ("I just keep getting above myself..."), "Christians and the Pagans" is a little too pat ("So the Christians and the Pagans sat together at the table/Finding faith and common ground the best that they were able/
And just before the meal was served, hands were held and prayers were said?
Sending hope for peace on earth to all their gods and goddesses). It's a nice, noble sentiment, that I enjoy, but it's also a bit too mushy to be an "A."
"Celebrate the Child" -- Michael Card
Contemporary Christian Music (CCM)lacks a lot of complexity. It can be repetitive and focus on choruses that sing well in worship services. A good chorus may not be the same thing as a good song to listen to. As a whole, I like Michael Card and I find many of his songs moving and a bit less superficial than most CCM. (Going through the the "C" songs made me rediscover the song "City of Doom" which I think is a really, really interesting mix of music and lyrics.) "Celebrate the Child" is a nice song, but as with many praise songs, there isn't much emotional fluctuation in it. The sentiment is nice, but there isn't much if any variation.
"Cry on My Shoulder" -- Bonnie Raitt
I confess that I mostly just like the tone of Raitt's voice. The song itself is pretty pedestrian:
And in the world outside
It can be harsh and cold
But if you need someone
I will be here to hold you
Cry on my shoulder
I'll help you dry your eyes
Cry on my shoulder
"City of Dreams" -- The Talking Heads
Harry Chapin once famously said that he had a hard time getting songs on the radio because they were too long. The Talking Heads sing songs that don't play well on the radio because they may not catch your ear right off the bat and pop your socks off. They do, though, have legs. "City of Dreams" is song that I like, but it never quite spikes. It's a bit too cerebral and abstract in its lyrics to make it easy to be great, though they are lyrics that might be really interesting if you think about them. The problem, though, is that I'm judging it as a song and not as poetry:
We live in the city of dreams
We drive on the highway of fire
Should we awake
And find it gone
Remember this, our favorite town