A CAPITAL IDEA
In order to cram the maximum amount of information into minimum space, editors of musical works-lists and catalogs use a convenient shorthand to avoid endless repetition of the words "major" and "minor." They use upper-case letters for major keys, lower-case letters for minor keys, thus:
Sym 3, Eb
Con 3, c
When providing such information in a context where space is not at a premium, many writers, recalling this capital idea but not understanding its correct use, use it where it's not wanted. The results look like this:
Symphony no. 3 in E-flat Major
Concerto no. 3 in c minor
Writers producing these muddled hybrids apparently distrust the ability of the word "major" to convey majorness all by itself, and therefore give it a little boost by capitalizing it. Conversely they seem to believe the reader too dull to grasp the idea of "minor" unless the tonality is named by a little letter. The writer is thus set up to commit such blunders as referring to some piece by a minor composer in some minor key, such as a minor.
To avoid this, remember the following: if a written letter is to stand for the name of that letter (as opposed to its sound), it should be capitalized. For instance, A-frame house, TV dinner, S-curve, I got a D in math. The necessity of this is immediately apparent if you try to read the following: a-frame house, i got a d in math, etc. Here is the form I prefer:
Symphony no. 3 in E-flat major
Concerto no. 3 in C minor
Recently an even sillier method of abbreviation has been making inroads into the programs of certain young musicians. According to this model, two of the cornerstones of the flute repertoire are identified as "Bach B- Sonata" and "Mozart D+ Concerto." It's shocking to see the likes of Bach and Mozart getting such grades!