Key Signatures

Ok, I know that I promised to keep the theory lessons to a minimum, on a need-to-know basis, so that you can be a better Trumpet player. Key signatures are important enough that you need to know what they are, why we bother with them, how they work and so on.

The simple reason that we see them is that they make the music easier to read – it’s less cluttered with sharps and/or flats. That lack of clutter comes with a small price … you have to remember what key you’re in while you’re playing in it. The key signature tells you what key you’re in* and in the process, which notes are to be played as sharps or flats. Most sheet music provides you with a friendly reminder of the key signature at the beginning of each line and trusts you to remember it for the next several seconds.**

Before we get into the weeds I should tell you that all of what follows is easier if you think about the notes on a piano keyboard. If that isn’t good for you, the next line of attack is to know your fingering chart or a chromatic scale pretty well.

Some pieces will change key and the new key signature will take over from the old one. You’ll occasionally run into a note that doesn’t obey the key signature and it will have a sharp, flat or natural sign on it. Those exceptions are called “accidentals”. Accidentals remain in effect for that note until the next bar line. In the example below there is not a flat for E in the key signature, but the song needs you to play E Flat. Because of the “remain in effect” thing, both of the E’s are flat. The next bar line cancels that accidental.

This explanation exists because the tunes in “First Easy Tunes for Beginning Trumpet Players” appear in two or three keys. I did that because a lot of beginning band methods present easy tunes in only one key. Some players can’t play all of the notes in some of those keys, and all players should know that any tune could show up in any of a dozen keys. Band method authors and I will present tunes in easy keys, but not necessarily the same keys. Every instrument has notes that are tricky and these authors have to make compromises.

Different keys exist because they make sense. If you’ve ever heard a group of people trying to sing Happy Birthday and sounding terrible, it’s usually because they’re singing in a variety of keys. If you’re in a band class, the only way to get you all to play the same notes involves getting you to obey key signatures. (Your band teacher is actually reading the music in at least 3 or 4 keys and in 2 different clefs all the time so they must be really smart.)

If a new lead singer joins a rock band but their voice isn’t working well the band might just play the same back-up parts in a higher or lower key until everything works. If a song in “First Easy Tunes for Beginning Trumpet Players” or anywhere else goes too high or too low, you can just play it in another key.

Key signatures and scales go hand-in-hand. There are major scales and minor scales that start on every note. The major scales and Natural minor scales are completely obedient to their key signatures. (Melodic and Harmonic minor scales require some accidentals but let’s not get into that right here.)

* Key signatures are groupings of sharps (#’s) or flats (b’s) that occur on the staff at the beginning of a piece of music, usually at the beginning of each line and occasionally in the course of a piece if there’s a change. Sometimes the key signature has nothing in it.

• Key signatures have either sharps or flats – not both. There is one key signature that has neither sharps nor flats in it, so all of the notes are “natural” – meaning neither sharp nor flat.
• The sharps or flats in a key signature always occur in the same order – always. If there are seven sharps in the key signature you’re in trouble – oops – I mean they are F#C#G#D#A#E#B# in that order. If there are three sharps they will be F#,C#,G#. I hope that’s clear. Some folks just memorize that order of sharps but most of us find it easier to memorize something like “Father Charles Goes Down And Ends Battle”. If there are flats in the signature they occur in the exact opposite order: Battle Ends And Down Goes Charles’ Father. So, if there are four flats in the key signature they’ll be Bb,Eb,Ab,Db.
• Most of the time we play in “major” keys so I’ll explain those first. C Major has no flats or sharps, so its key signature is empty. There appears to be no key signature. If the key signature has any sharps in it then the last sharp is the 7th note of its scale. In other words, one semitone above the last sharp names the key. If there are two sharps (the last one is C# because they always occur in the same order) the Key is D Major. If the key signature has any flats in it, the last flat is the fourth note of its scale. That’s not as easy to figure out, but if there are two or more flats then the second last one names the key. If there are 3 flats then you’re in Eb (remember Battle Ends And …). That leaves out the key signature with only one flat – it’s a Bb and we just have to remember that it is the key signature for F Major.
• Minor keys use sharps and flat in the same order as major keys but they have different relationships to them. The easiest way to figure them out is to know the key signatures of the major keys and simply count down three semitones from what that would be. If there are two flats they are Bb and Eb; the second last one is Bb so that’s the Major key that you’d be in; so we go down three semitones to A, Ab then G. G minor is the minor key that has Two flats. That happens to be the 6th note in the major scale, so that’s another way to find the minor.
• Finally, it can sometimes be tricky to know if you’re in a major or minor key. The answer to that is almost always clear if you look at where the melody leads, what the harmony is doing or what kind of accidentals you’re coming across. There are some pieces that seem to defy categorization and that’s ok – We’re keeping it simple today. Key signatures are really just about un-cluttering the music. They’re supposed to help even if they are likely the single greatest source of wrong notes in beginning bands
• Oh yeah: some tunes have key signatures that tell to about notes you don’t even have to play. For instance you might have an Ab in your key signature and find that there aren’t any A’s in your part. Don’t worry about it. It seems like useless information, but it does tell you what key you’re in so there’s that. People who write music care about it being correct.
• There’s actually more to know but this is already a lot.

** Jazz Band sheet music usually doesn’t remind you of the key signature at the beginning of each line. That’s been the case for generations and probably started when people hand-copying parts thought it was a waste of time and space. They also probably thought that if you couldn’t remember what key you were in you had no business playing their music. The tradition continues.