How to quickly know the notes in a key?

Question

I'm a guitar player. I know about all the basic music theory for the simple major, minor and pentatonic scales. I know that a major chord consists of the 1,3 and the 5 and a minor of the 1, the b3 and the 5 and the order of chords in the major and minor keys.

The problem is: I can only make a song with the right chords if I note down all the notes in the key and then find the corresponding chords, this is of course a very time-consuming way. I want to be able to quickly know the notes in a key and which chords are going with that without having to note everything down. How can I practise this effectively, are there any tricks?

Answer 1

In my opinion, the quickest way would be through fluency of key signatures.

In other words, you should know immediately what accidentals are found in D major (F# and C#). In this way, your brain doesn't have to process all seven pitches in a key, only the ones altered from their default "natural" state. When you get to something gross like G-flat major, you can do it the opposite way by thinking "everything is flat except F."

If you're unfamiliar with key signatures or the order of sharps/flats, What use is knowing how many sharps or flats a key signature has? may help.

Answer 2

Knowing the circle of fifths will go a long way to helping with which notes belong to which keys. Starting at 12 o'clock, with C major (no # or b), it's like a clock face. At one o'clock, there's G, with the note before G sharpened - F#. At two o'clock lives D, with its penultimate note #- so imagine C# as well. It continues round to six o'clock, adding those leading notes - where F# lives.

Going anticlockwise, count 4, so eleven o'clock is F (one b - Bb). At ten comes Bb, with a cumulative Eb and Bb. That pattern continues to six oclock, where it matches up with F#, now called Gb.

This is more simple than it sounds! But has helped countless musos finding keys/notes etc.

The chords which go with each other in a key (diatonic) are I, ii, iii, IV, V, vi, viio, translated from the notes in the scale from that key. I IV and V are maj., ii iiiand vi minor, viio dim.

So, putting it all together, say we're in E, with 4# (F# C# G# D#), the chords work out as E, F#m, G#m, A, B, C#m and D#o.

A mnemonic may help - for example, with sharp keys Can Greedy Dogs Always Eat Bones F#ast. I'm sure you'll come up with a more appropriate one! It's something I get students to do. Personalised ones are so much more appropriate!

I wanted a concise, simple answer, but this is as simple as it comes. Work through gently, and with use, like most things, it'll get easier!

Answer 3

The fact that you are a guitarist suggests the niftiest answer: the layout of the fingerboard is itself a great learning tool. Play, say, an A major scale starting on the fat string at the 5th fret using the common fingering of 2,4 1,2,4 1, 3, 4. For now, just go one octave and finish on the 4th string.

Those 8 notes give you the 8 degrees of the scale: 12345678. Keep your hand in position. The major triad will fall under your fingers: 2,1,5 (A C# E). The names of the main chords in any key, I, IV and V, based on scale degrees 1, 4 and 5, can be memorised. I and IV are on the same fret, one string apart and V is on the same string as IV but two frets higher. At first you will have to count up from known notes to name the notes, but you will start to memorise them in time.

The next step is to work out what notes are in the main triads, I, IV and V. Well, you already know triad I (notes 1,3 and 5 from A major scale; A C# E). Stick your 2nd finger on degree 4 (5th string, 5th fret). That note (D) is the root note for chord IV (D major). It just so happens that you can use the same old major scale fingering pattern starting on D (5th string 5th fret) to find the notes of the D major scale. Notes 1, 3 and 5, falling under fingers 2, 1 and 4, are the notes for the D major triad. You work out Chord V the same way. You know that the 5th degree of the a major scale falls under your 4th finger on the 5th string (7th fret).So now you need to play the major scale starting on that note. Shift your hand and put your second finger on that note (E, 5th string 7th fret). Now use the same old major scale fingering pattern, 2 4, 124, 134 to work out the notes in the E major scale and then pick notes 1, 3 and 5 to form the triad.

Hopefully you will come to recognise that fingers 2, 1 and 4 will always give you the notes for a major triad. This works on strings 6 and 5, 5 and 4 and 4 and 3. It doesn't work for strings 3 and 2, but it works again for strings 2 and 1.

Hopefully you will also come to recognise that the root notes for chords I and IV are always on the same fret on adjacent strings and that V is two frets up the neck from IV. This remains absolutely constant right up and down the neck for all keys, so if you can visualise it for A major you can visualise it for all keys.

As for working out what chords you can use, the following is a good starting point: Chord I is major Chord ii is minor (note the lower case roman numeral for 2 indicating that it will be a minor chord) but that rule is often broken and a dominant 7th chord substituted. Chord iii is minor Chord IV is major Chord V is major or dominant 7th. In some cases, a minor seventh can sound cool too. Chord vi is minor

Chord vii is diminished.

The major keys will keep you busy for a while, but as a taster, for minor keys chord i is minor, chord iv is minor and chord V is major (dominant 7).

So in summary: Use the scale fingering pattern 24 124 134 to find the degrees of the major scale. Use the pattern, 'I and IV same fret adjacent strings and V is two frets up' to name chords I,IV and V. Use the same old fingering pattern, 24 124 134 again to find the notes in scale of Chord IV and again for Chord V, then use notes 1, 3 and 5 to for the triad for Chord IV then Chord V. In this way your fingers will find the right notes long before your brain does. Plenty of people stop there, but once you've got used to using these patterns get into the habit of nutting out the note names and saying them out loud. You won't regret it.