Before doing anything, you should work out the key which contains song so that you feel yourself in a better position to implement all of your knowledge about scales. Experience can benefit you a great deal in this case. And moreover, there isn't always a guaranteed pattern, but a little knowledge can go a long way towards helping you with this.



Sheet Music

You have some sheet music for the song you are interested in. This is a bit easier as a reliable formula can be used in this case. Naturally, if you don't read music this may not seem easy to you.

If you understand music, you may already have knowledge about key signatures. The key signature is actually a group of symbols at the beginning of the piece of music, in the form of a list having either a number of sharps (#) or flats (b). The sharps and flats are constantly listed in a special order, which is found by the Circle of Fifths, although that isn't noteworthy for this.

Search the internet for sheet music with:

The key of C ??" no sharps or flats

The key of E ??" four sharps

The key of B flat ??" 2 flats

Now, imagine you have understood the notes with the help of above described staves, you are able to determine the key of the song you are interested in through the use of following simple rules.

1. In case of no sharps or flats the key must be C.

2. In case of sharps, notice the stave line on which last sharp symbol is placed, and go up 1 degree of the scale. In the above stated example, we have 4 sharps, F#, C#, G# and D# (again, resulting from the practice of the circle of fifths). The last sharp is D# - one point up from that is E. Other way to put this is that this sharp sign imparts you the 7th of the scale. One up from that is the 8th, or root, granting you your key. So the example above is in the key of E merely as we guessed.

3. If there are flats, look at the stave line that carries the last symbol is and get down 4 degrees in the scale, or to put it another way, the final flat sign gives you the 4th of the scale. In the example above we have Bb and Eb ??" 4 degrees down from Eb is Bb, which is the key (Eb-D-C-Bb in specific order). But if you are stressed to work out the key, this rule can't help you properly, and according to me there is really another better trick for flats. This is based on the fact that we are going backward and the circle of fifth. You should not worry about the details for now and trust me when I say that each flat in a key signature is separated by 4 degrees, therefore you can get the exact key signature by looking at the flat instantly before the last one. This rule doesn't work for one flat, so you just need to keep in mind that one flat is the key of F. In our example, the last but one flat was Bb, which is our key.

Thus, apart from one, you can immediately deduce the key by practicing the above rules and a sheet of music. Another noteworthy point is that every leading key has a related small-scale key. This is so because they share the same key signature. Thus you can narrow it down to 2 possibilities utilizing the key signature, after that, you need to focus on if it is leading or minor.