Question about keys -- what are they and what do they do?

sort of.

The key tells you which scale you're using and hence what the chord progression is -- which chords and which notes fit the song (typically).

That's a fast and dirty answer. I don't know if you're looking for more detail?

I don't understand why people can't sing in any key though?

What keys do is give a sense of organization to sounds. You've got 12 chromatic notes available, and any one of them alone sounds just fine... but when you start combining notes into melodies, some notes will fit better than others.

Over time, we've developed an organizational system that sorts out notes into keys. That way we know that if we're "in the key of G", certain notes like F# will fit in, while other notes like Ab will sound a bit funky... that doesn't mean we can't use the Ab, just that it's not typically going to be used.

Key's don't change the pitch by themselves -- but they do select the pitches that are going to belong in the key. In G, you'll use F#; if you go up a half step to Ab, you won't use the F#. Ab will sound a half step higher, but it uses some different notes (like F instead of F#) and some of the same notes as G - the note C, for example, will appear in both keys, and the pitch of C will be the same in either key.

Knowing a certain fingering, like the notes in the key of F, will allow you to play any key by moving that fingering. If you move it up two frets, you'll be in the key of G - that's called transposition. Your new position will be in G, though, not in F two frets higher. Otherwise you'll confuse musicians you're playing with - a saxophone doesn't have frets, so your sax player won't understand "F two frets higher", but he will understand the key of G.

If you're talking about vocal range, the key you sing in can be different for every song. Looking at some sheet music here, I've got two tunes by CCR - both in the key of C. "Down on the Corner" ranges from middle C (the lowest note) to the A above that. "Green River" ranges from G (just below the highest note in Down on the Corner) to the Eb above that - which is more than an octave higher than the lowest note in the first tune.

Let's say your vocal range goes from middle C to the C one octave higher. You'd be able to sing the first song, but not the second, in the key as written. To sing Green River, you'd want to transpose it down at least a minor third to put all the notes in your vocal range. If your range ran from D to D, you wouldn't be able to sing either song as written - you'd transpose the first one up, and the second one down. It all depends on the range of the melody, rather than the key signature.

Finally, keys like Bb are used all the time. Keys like C# are used fairly rarely... it would have 7 sharps, and it's easier to write in the enharmonic key of Db, which has only 5 flats. If you mean a key signature that has only a C# and a Bb in it, that would be extremely rare - experimental key signatures are only used in experimental music.

Keys unlock music.

Ha, ha, ha, ha, ha. I kill me. :D

Keys unlock music.

Ha, ha, ha, ha, ha. I kill me.

Yeah, keep making jokes like that, and so will we. :evil:

i didnt get that right away.. till i saw you laugh and then it made sense..

*feels like an idiot*

Kinda following on from the earlier discusion, I have the chords for Wonderful Tonight which starts G, D, C etc. nice and easy for me, can I still play the riff on the 2nd string fret 10? (10->12,8,10; 10->12,8, 9-3rd string, and so on) Or do I need to shift the riff/solo to different notes - and if so how would I do that.

(One answer might be if it sounds OK play it!!)

When you're trying to duplicate a song, it's not theory so much as ear training - because you probably don't know right off what scale is being used. The Clapton tune is in G, and the riff ends on an E note... so does your fingering, so it works.

If you were going to do the tune in a different key, that's where theory comes in - let's say it's too high for your singer, and he wants to do it in F. Everything moves down two frets - the chords would become F, C, and Bb, and your riff would start on the 8th fret.