Question on notation

[sensei]

Hey all,

I'm learning a song, that has a flat on the 'B' in the key signature. I supose that means it's in the key of B flat?

Any way, all b's are flat, until I get to an accidental noted as a B natural. No problem. Here's the question though, Does that "natural" apply ONLY to the b it is next to?

And how about this... if any note has an accidental sharp, are further instances of that note sharp until a 'natural' sign changes it?

Thanks for any input...

[aeolian]

Hey all,

I'm learning a song, that has a flat on the 'B' in the key signature. I supose that means it's in the key of B flat?

Actually that is not correct. If the key signature has a flat on the 'B' (middle line of the staff) it just means that the note B should be played as a Bb for the piece, it does not mean that piece is in the key of Bb. For example, the key of F has these notes in the scale: F G A Bb C D E, so with a Bb but everything else being natural you get the key of F. Think of the sharps and flats in the key signature as forcing notes to the proper tone to create a particular scale.

Any way, all b's are flat, until I get to an accidental noted as a B natural. No problem. Here's the question though, Does that "natural" apply ONLY to the b it is next to?

And how about this... if any note has an accidental sharp, are further instances of that note sharp until a 'natural' sign changes it?

Thanks for any input...

I thought I knew the answer, but I had to look it up to see that I don't really have a complete understanding. If an accidental is applied to the Bb it turns back into a B, but only the bar that the note is in (unless the note is continued into the next bar). The next occurrence of B will revert back to the key signature with a Bb.

[markb]

It's in the key of F with one flat. The accidental Bnat would likely be played over the II chord (Gmaj). Does the song use a II-V-I turnaround anywhere, perhaps? All Bs should be played as Bb unless specifically noted as a natural as aeolian noted (sorry!) above.

[Ro3b]

Just some handy info. In key signatures that have flats, the next-to-the-last flat in the signature will be the major key. For example, if you see three flats in the key signature, they'll be in the order Bb-Eb-Ab: you're in the key of Eb major. (Or G minor or any of several associated modes, but let's not complicate things.) If you see five flats in the key sig, they'll be Bb-Eb-Ab-Db-Gb, so you're in Db major. The key of F is the only one that doesn't fit this pattern because it only has one flat: Bb.

In key signatures with sharps, go one half-step up from the last sharp in the key sig to determine the key. For two sharps, you'll see F#-C#, so you're in D.