I want to understand what this musical entry on wikipedia means.

February 23, 2013 8:18 PM

I am also looking for the easiest way to hear (or generate) these sounds online.

If you look at this wikipedia entry (http://en.wikipedia.org/wiki/Major_chord) at the bottom, there is a table showing 17 Major Chords and the three notes that make them up. Here are my questions about this table:

(1) In some of the entries (like c#) the major third column or perfect fifth column has another note in parenthesis. What does this mean? Does it mean you can generate that chord with either of the two possible 3 note combos? And if there are two ways to generate this chord, don't they sound different? Is the non-parenthesis one more common or more sonorous?

(2) Are these 17 all the major chords? Or are this just a list of examples of major chords?

(3) Do these 17 major chords (and three componant notes) listed in the table represent all the notes on a standard piano keyboard, or if I were to map all the named notes on the table to a standard piano, would I have keys (black or white) on the piano that haven't been represented? If so, what notes would these be?

(4) Some of the entries on the table are noted with a symbol that wikipedia (on mouseover) says is a "doublesharp". What is a double sharp?

(5) Will these all sound the same regardless of the instrument they are played on (tuba vs. piano vs. oboe for example). What I am really wondering is: If someone has perfect pitch, will they be able to pick out the chord and root notes completely independently of what instrument the chord is played on? I assume this is yes, and is contained in the defintion of "perfect pitch", but are there any edge cases?

(6) I want to hear what these 17 major chords sound like. Is there a place online where I can just hit play and hear them, or (second best) an online music player where I can type in the note names and hear the chord. (I have no musical knowledge and wouldn't know where these notes are on a virtual keyboard.)

Thanks.

posted by tangyraspberry to Computers & Internet (19 answers total)

The notes in parentheses are enharmonic.
posted by wondermouse at 8:22 PM on February 23, 2013

There are only 12 major chords. Some of those listed are alternative means of writing the same chord (c sharp and d flat are the same note-- look on a keyboard)

The easiest way to play all these is to just play them on a piano, it only takes three fingers. Each major chord is constructed exactly the same way. Take the root note, then count 4 keys up (including the black keys), press that one, and up 3 more from that one. If you move three and then 4 more instead you have a minor chord.
posted by empath at 8:38 PM on February 23, 2013 [2 favorites]

And yes, if you have perfect pitch, it doesn't matter what instrument.
posted by empath at 8:40 PM on February 23, 2013

You can use the virtual keyboard here.

The keys are labeled. You can select chord mode on the left, then click on multiple notes and hit "play chord" to hear what they sound like in combination.
posted by bunderful at 8:40 PM on February 23, 2013

In some of the entries (like c#) the major third column or perfect fifth column has another note in parenthesis. What does this mean?

Just in case wondermouse's "enharmonic" link was a bit too technical; the note in the column and the note in parenthesis are the same note. Look at the virtual keyboard that bunderful linked to - there's no key between E and F, so there's no actual "E#" (E sharp), it's just another way of noting "F."

Oh yeah, just for basics, "#" means "sharp", a half-step up; "b" means "flat", a half-step down. "Double-sharp" is up two half-steps, which, no surprise, is actually a whole step.

And so as empath points out, C# and Db are the same notes, the same chord.

Actually, the notes in parenthesis are the more common names for the notes. If you asked me to play a C# major chord I'd play C# F G#.

The wikipedia table is noted the way it is because it's strictly following the rules of building major chords with a root, a major third, and a perfect fifth. Strictly technically speaking, a major third up from A# is C double-sharp. In practice, double-sharps and E# are very rarely used.
posted by soundguy99 at 1:23 AM on February 24, 2013

Response by poster: Wow. these answers are great. I am really starting to understand this. I have two follow up questions.

(1) I see (on that great virtual keyboard) that (for example) from D you can go half a step up of half a step down, producing D# or Dflat. Does the piano layout mean (a) there is no F-flat/E# ON a standard paino or (b) that this note is not used and notated in western music? In other words, if you play violin is E# something you'd play while for a pianist it is not?

(2) OK, I get that notes are just sound waves at different frequencies. And that A is just the name we give to 440. So when you say "step" and "half-step" what is the change? ie. A = 440. So, (A+x) = B. What is x?
posted by tangyraspberry at 9:12 AM on February 24, 2013

E and F are half steps apart. By convention, if you use all the white keys, starting with C, you have the C major scale. It could have been done some other way, but everyone settled on C. The black keys (sharps and flats) are needed for scales that start with other notes.

A half step is approximately 1.059 times the previous note (or to be exact, the 12th root of two). That frequency is used, because if you go up 12 semitones, you've doubled the frequency, bringing you back to the original note, but an octave higher)

And as an aside, while a pure sine wave at 440 is an A, any physical instrument actually produces the root frequency plus a series of overtones at whole number multiples of the root, so an A on a violin will include 440 and 880 and 1320, and so on. This partially explains why chords work. 440 is an A. 880 is an A an octave higher, but 1320 is closer to an E, which is part of the major chord with A. So an E played at the same time as an A reinforces it and makes it sound richer.
posted by empath at 9:38 AM on February 24, 2013 [1 favorite]

Does the piano layout mean (a) there is no F-flat/E# ON a standard paino or (b) that this note is not used and notated in western music? In other words, if you play violin is E# something you'd play while for a pianist it is not?

All the notes are available to all instruments (obviously not all ranges - both a piccolo and baritone sax can play a C but not the same C - in other words, one will be much higher than the other).

Some notes have names that are used less frequently than others. E# is the same note as F. F-flat is the same note as E. Usually you wouldn't say E# unless you were in a theory class discussing how to build a major C# chord. Same for F-flat - applicable in theory but less so in practice.
posted by bunderful at 10:43 AM on February 24, 2013

So (a) is closer to the right answer, but it's really not about western or eastern. It's more that it's easier to be understood by talking about the note in its simplest terms - F rather than E#, E rather than F-flat, C rather than B#, etc.
posted by bunderful at 10:50 AM on February 24, 2013

In answer to your follow-up question about if E# is something you'd play on the violin or any other instrument: Whilst playing a piece on any instrument you could come across an E# in the music - composers are (more or less) equally likely to write the note E# for a violin, piano, flute etc. On all of these instruments it would still sound the same as an F and would be played the same way as an F. The reason why you might find yourself playing something written as an E# rather than always just an F is to do with key signatures (this might lead to more questions but that's fine!). I can explain in more detail if you would like.

To address two of your original points:

5) Yes, someone with perfect pitch would be able to pick out the notes of a chord regardless of instrument. The only thing that would change is the timbre (tone-colour) of an instrument, like the way that a flute sounds breathy and a trumpet sounds brassy. Also not all instruments can individually play the notes of a chord simultaneously - a piano can because you just press down the keys at the same time but any instrument where sound is created using breath (flute, clarinet, sax, trumpet, tuba etc) can only sound one note at a time.

6) Teoria is a great website for learning about the theory of music. This page will play you all the major chords.
posted by Lotto at 11:08 AM on February 24, 2013

Working off empath's answer, see Equal temperament in Wikipedia.
posted by soundguy99 at 12:03 PM on February 24, 2013

Response by poster: I am really learning a lot... a few more follow up questions:

(1) Why have the notation for flat at all? After playing with the chord generator (great link, thanks!) it looks like you can express everything with the note name (A,B,C,D,E,F,G) and the # symbol. Why have two names for the same thing?

(2) So I can see that different C's (and A's, etc.) appear many times on a typical keyboard (8?). When you are reading music, how do you know which C is being refereed to?

(3) Back to this idea of perfect pitch, does someone with perfect pitch recognize the "A-ness" of 440, 880, 1320 like I experience three different hues of red all as "red," or is their experience instead analogous to experiencing sound1 (440) sound2 (880) and sound3 (1320) like I would experience the abstraction of "car / boat / airplane" as all distinct *different* things that fall under the abstract rubric of "transportation."?
posted by tangyraspberry at 1:11 PM on February 24, 2013

(1) On a piano it's not strictly necessary to use flats, but they make music easier to understand in the same way good spelling makes English easier to understand.

For example, a major scale starting on C goes C D E F G, with the letters following one after the other in sequence.

If you took the same pattern and started on G# and just used sharps, you'd get G# A# C C# D#. The fact that it skips over the letter B and uses the letter C twice is at odds with the way people hear it, which is as 5 consecutive notes. So people prefer to spell it Ab Bb C Db Eb (you could also spell it G# A# B# C# D#, and in certain contexts they do, but other things being equal it's nice to avoid spellings like B# for C).

(2) Written music doesn't use letters, it uses positions of circles relative to horizontal lines. The higher the pitch, the higher the circle. Each C looks different.

(3) The former. A is A, as Ayn Rand said.
posted by dfan at 2:05 PM on February 24, 2013

Why have the notation for flat at all?

It can certainly make reading and writing music easier. See Modern staff notation for a quick view of how music is written out.

Look at the "circle of fifths" diagram in Lotto's "key signature" link. To note the key of B-flat major the composer adds 2 flat marks at the beginning of each line of music, on the B and E staff markings. This tells the player to always play B-flat & E-flat (instead of B and E natural) unless otherwise noted.

They could write it as A-sharp, which would be the same notes, but that would require 10 sharp marks at the beginning of each line, which takes up a lot of space and would be more difficult to read & remember.

There's also a convention of using sharps when ascending to a note, and flats when descending to a note. If I'm remembering my long-ago theory courses correctly, this convention (and a lot of other things about how "modern" music is analyzed, described, and notated) is derived from ancient Greek theories about music, which were interpreted, analyzed and somewhat codified as part of the development of "Western classical music."

See Classical Music and Musical mode for some historical background.
posted by soundguy99 at 9:14 PM on February 24, 2013

There's also a convention of using sharps when ascending to a note, and flats when descending to a note.

To follow on from my spelling-convention explanation from two comments ago, this is because A#-B makes it a lot clearer that you're going up than Bb-B, and Bb-A makes it a lot clearer that you're going down than A#-A. The notes end up at different heights in the music notation if they're spelled with different letters, and here that's useful.
posted by dfan at 4:46 AM on February 25, 2013 [1 favorite]

(3) The former. A is A, as Ayn Rand said.

Well yes and no. They can certainly tell you which A is being played.

Btw, it's much easier to teach yourself something called relative pitch, as opposed to perfect pitch. That is, when notes are being played sequentially, how far apart on the scale they are. All it takes is playing around on the piano, playing various chords, looking at sheet music while listening to songs, etc. Especially intervals like perfect fifths.
posted by empath at 5:03 AM on February 25, 2013

I highly recommend you pick up Music Theory For Dummies and download a music app like GarageBand if you want to learn this stuff. You don't need years of piano lessons for this stuff to make sense.
posted by empath at 5:08 AM on February 25, 2013 [1 favorite]

(3) The former. A is A, as Ayn Rand said.

Well yes and no. They can certainly tell you which A is being played.

Sorry, I was being cute. I meant that tangyraspberry was correct in saying does someone with perfect pitch recognize the "A-ness" of 440, 880, 1320 like I experience three different hues of red all as "red"? I can certainly distinguish an A-440 from an A-880, although with some timbres (e.g., certain organ stops) it does become more difficult.
posted by dfan at 5:10 AM on February 25, 2013

empath is right. There's also a coursera class you might find helpful.
posted by bunderful at 7:03 AM on February 25, 2013