Music answers, pt. 3

Follow up from drquuxum: Follow-up question: Whenabouts/whereabouts did those notations become standard (or at least commonplace)?

Blame Guido d'Arezzo [~991-1033CE]for the staff notation and unifying music written on a 5-line staff, not some on a 4-line staff or a 3-line staff depending on region.

Clef history from Wikipedia: The clefs developed at the same time as the staff, in the 10th century. Originally, instead of a special clef symbol, the reference line of the staff was simply labeled with the name of the note it was intended to bear: either G, F, or C. These were the 'clefs' used for Gregorian chant. Over time, the shapes of these letters became stylized, eventually resulting in the shapes we have today.

From psywildfire: New question: what are the differences between major, minor, and 7th keys and how did they get those names?

New answer: Major and minor describe different scale patterns. They are not 'keys' as such, even though you'll hear a certain piece described as in "a major key." Major and minor are modes. Go grab a piano. Done? Now, play from C to the next C up, only the white keys. Congrats, you've just played the C major scale. The major scale pattern is a series of whole and half steps. A half step is the interval of two keys directly adjacent, with no other keys in between. A whole step, then, is two half steps put together, so that there's one piano key (white or black) in between. C to D is a whole step. So is D to E. Not E to F, that's a half step.

So, if the C major scale is C - D - E - F - G - A - B - C, the steps in between are W, W, 1/2, W, W, W, 1/2. Any scale that follows that pattern of whole and half steps is a major scale. There are 12 different major scales, making the 12 different keys.

Now, minor. A minor scale is simply a major scale that starts in a different place. Still got that piano? Good. Play from A to A, no black keys. That's the A minor scale. Where is A in the C major scale? The 6th tone, or degree. So, to get a minor scale simply play a major scale starting on the 6th degree of any major scale.

I need to move on cuz there's lots to explain. :-) '7th' describes an interval, two tones that are 7 names apart. Count all the notes in the C scale above. You'll get 8. So, from C to C is an 8th, better known as an octave. A 7th, then, would be from C to B. Now, no matter what you add to the C or B, it's still a 7th, whether it's C-sharp to B or C to B-flat, or C-double-flat to B-double-sharp. The name of the tone determines the interval degree (7th, 5th, etc.) The usage you've probably heard is with a chord, like an F7, or "F seventh" chord, or maybe a G dominant 7th chord. Well, an earlier answer defined a chord as three or more notes played at once, like F-A-C. If you count those tones, and F=1, then A=3 and C=5. So, take a note and add the third and fifth above it and you get a chord. A seventh chord simply also adds the seventh degree from the first note of the chord. In the case of F, that would be E. So, F-A-C-E played together would be an F major seventh. F-A-C-E-flat would be an F dominant seventh chord.

Lastly, why the names? Simply, a major interval is larger than a minor interval by one half step. Take whole and half steps themselves. C-D is a whole step. If C=1, what will D=? Yes, '2'. So, C-D is also called a major 2nd. Now, there's a black key between C and D. In order to keep the interval a 2nd, we need to call that black key a D-flat. So, from C to D-flat is a half step, but it's smaller than C to D, so that interval is a minor 2nd. Why call the scales that? Because in all major scales the intervals of a 2nd, 3rd, 6th and 7th are major. In all minor scales those same intervals are one half step smaller, so they're minor intervals.

*whew!!*

From madbard: What equations best describe how 19th century French violin purfing impacts the instrument's resonance?

I don't like you. :-P

Firstly, it's purfling, and secondly, I'm not into what the French did with violins in the 19th century. So there.

Last one for tonight, folks:

From klari: Oooh! Do C clef! Why does it move?

Easy- To avoid ledger lines!! In fact, if you check out the Wikipedia article on clefs, you'll see that all the clefs move/d! And it's all just to avoid having to read a bunch of ledger lines! Sing-- er, vocalists have used this more than others historically, but today it's down to tenor and alto clef both using the C clef. You will also hear European conductors (moreso than our US counterparts) say how they can read so many different keys at once by changing the clef of the instrument rather than transpose mentally. It's like reading a trombone part on alto sax. It works so long as you change the key signature correctly (which requires you add three sharps).

More answers to come!