I must admit I don’t understand Zebra’s description of C sharp minor, as poetic as it is. But this is also the key of Beethoven’s famous “Moonlight” sonata, so it can’t be all that bad. 
You’ll have me humming that tune from my childhood all day now!
“There was was just a-standin’ in the street”
Back to the OP - there’s another explanation of scales, with audio examples, here
I think that E flat major is an electric elk called Simon.
Is it conventional to present the keys in writing in a certain order (for example, that given by K364)? I’ve also come across that order inverted, i.e. starting with F-sharp major and ending with G-flat. Which is more common?
And is it okay to simplify and explain keys to a kid as follows:“There are 12 major keys, one for every letter of the musical alphabet (e.g. A-major, Bb-major, B-major, C-major). Similarly, there are 12 minor keys (e.g. A-minor, Bb-minor, B-minor)”?
I’d say that was close enough, with one caveat, thus:
Each note can be known by more than one name (B natural or C flat; note that the double-flat and double-sharp names can be discounted). We use a key based on either name if the resulting key signature doesn’t include double sharps or double flats. There are only a few notes for which there are two enharmonic key signatures (C flat and B; F# and G flat; C# and D flat).
Other keys would have more than seven sharps or flats, for instance “D# major” which would have nine… so we usually use E flat major instead. But these have a sort of in-between existence, for instance just as a piece in C major can modulate into G major, for which you need an F#, a piece in C# major can modulate into G# major, for which you need an F##. But they’re not represented by actual key signatures; the odd notes are provided with accidentals.
Go ahead.
What about the eighty-eight musical keys, them black and white ones, on that there pie-anno? 
What well known pieces were written in B major? Is it a commonly uses key? If not, why not?
There is a reason for all these questions, but it cannot be divulged at the moment!
Many composers have written collections of pieces which systematically include every key (e.g. Bach’s two Well-Tempered Clavier books which consist of a prelude and a fugue in every key, or Chopin’s Preludes for piano*.
I can’t think off hand of any famous classical pieces in B major, though I’m sure there are at least a few. Incidentally, The Daily Show theme is in B major.
It is a less commonly used key, mainly because it doesn’t sit well on most, if not all, instruments. C major is easiest on piano, along with the closely related keys G and F. Various wind instruments are most at home in Bb, Eb, and Ab so those keys are common, especially in jazz. On guitar the open string keys E, A, D, and G are most common. But I just don’t know of any instrument well suited to B major.
Oh there is that one really famous short fugue in B major, composed by yours truly.
It’s actually officially in Cb major which is the exact same key as B major. It was written as kind of a joke. My GF’s mother asked my GF “so what’s moe up to, writing a fugue in Cb or something?” So I did.
What Moe says.
Somewhere recently in another music-theory-related thread I compiled a list of violin concertos that are in A, D or G - it covered the majority of the well-known pieces. Because these keys, and their related keys, suit virtuosic idiomatic violin writing perfectly.
I can’t off-hand think of any ‘major’ composition in B major. An additional difficulty in a large-scale work in this key is that you would very quickly find yourself dealing with keys at the limits of ‘normality’ in the way we’ve described - even F sharp major, the key which will probably see second-most use in such a piece, introduces the awkwardness of E sharps. So while the key itself isn’t particularly difficult to deal with, the onward implications of using it within tonal music make it an undesirable choice.
On the other hand, there’s no shortage of sections of music which use B major, as one part of a larger structure.
Well, there actually are people who will argue–and do have a point–that B major is actually the easiest key on the piano were it not for the notation. If you want to know why, go play a B major scale on the piano. It’s the key most suited to the shape of your hand. In fact, your can play some blazingly fast riffs in B major that cause you fingers to trip over each other in C major. For the same reason, F is often considered the “fastest” key to play in by blues keyboardists. (F, A-flat, B-flat, B, C, E-flat).
As for B-major, while it’s not exactly popular, Schubert has a mass in B-major. Brahm’s First Trio for Piano and Strings is in B-Major.Off hand, Chopin’s got a Prelude, a Nocturne (Op. 9 No. 3, although his No. 1 and No. 2 are the most well-known), a Mazurka, probably an etude or two. It’s out there.
String instruments play better in sharp keys. The open strings are all the root tones of sharp keys, which is the main reason, I believe. Wind instruments are virtually all in flat keys - or C - and they tend to play better in those keys. Even an instrument such as a trombone, which is basically a C instrument, has a B flat fundamental.
Although the latter statement is correct, this doesn’t necessarily mean that string instruments (by which I presume you mean the violin family) ‘play better’ in sharp keys. As I said, G, D and A are common keys for string writing, because the open strings offer extra resonance, and fast fingerwork & double-stopping is often easier in such keys. But go beyond them, to E or B majors, and these benefits disappear - it’s nothing to do with sharp keys per se, but with the specific tunings of the various strings.
Yes, better said.
For a similar reason, accompanists greatly prefer to play Richard Strauss’s song Ständchen in the original key of F# major rather than a transposed key, because all those black notes fit the fingers so well. The piano part, which moves very fast in a sort of pianissimo filigree, is annoyingly difficult in other keys (like D major for low voice, which is easier to read).
I’m not sure I follow, but I am being educated, and your sentence conjures up images of poor Manuel’s “filigree” Siberian hamster, AKA rat!
Moe, a very pleasant Bachesque interlude to break up my morning’s slog.
Incidentally - and I feel I must share something back with you kind people - I found this website particularly helpful and nonmusician-friendly. Might help you in your tutoring, etc.
What’s an “open string”?
An open string is a note played without pressing down on a fret. Denoted as “0” in tablature.