Introduction to Harmonic Mixing|
Posted on Monday, August 08 @ 21:27:48 EDT by qualia
Topic: How To DJ
In order to mix harmonically you must understand a bit of music theory and know the keys of the songs you are mixing. Taking the time to do this will improve the quality of your mixing by allowing you to combine melodies and harmonies without clashing. It will also help you learn to play along with your music if you have any instruments.
Music Theory Sounds are classified into pitch groups described as notes. There are 12 notes which repeat themselves. The keyboard is a good visualization:
The notes can continue in either direction. Due to the layout of the traditional keyboard, the black notes are named relative to adjacent white notes (which is why there are 2 names for each black note). Sharp (#) means above while flat (b) means below. Each of the 12 notes is related in frequency in that they are all multiples in powers of 2. Every 12th repeating note on the keyboard doubles in frequency. All adjacent notes are evenly spaced intervals called half-steps. The interval of 12 half-steps (for example, from a C note to the next C note) is known as an octave. As a DJ, you must understand that most songs have a key, or tonal center. Keys are based on scales, usually major or minor. Scales essentially describe subsets of notes that go well together. The 1st note of the scale is the tonal center, known as the tonic note. The 4th and 5th notes of a scale are known as the subdominant and dominant notes, also referred to as perfect 4ths and 5ths. Whether the scale is major or minor, subdominant and dominant notes are always 5 and 7 half-steps up from the tonic note, respectively. It is important to be able to determine the notes of a key. The easiest way is to remember the pattern of intervals that form major and minor scales. Although there are multiple minor scales, we will simply refer to the natural minor. Knowing that a half-step (H) is the interval between 2 adjacent notes and a whole-step (W) is 2 half-steps, the scale patterns are:
If you forget these patterns you can refer to the keyboard. The major pattern uses all white notes from any C note to the next C. Similarly, the minor pattern uses all white notes from any A note to the next A. The fact that C major and A minor share the same notes is because they are relative keys. Every major key has a relative minor, and every minor key has a relative major. To make sure you understand, the notes of the C minor scale are shown below. Songs in C minor would generally use these notes, with C being the tonal
- major - W, W, H, W, W, W, H
- minor - W, H, W, W, H, W, W
Playing any notes in succession forms melodies, while playing them at the same time forms chords, which are the basis of harmony. There are many types of chords. Common major and minor chords use the 1st, 3rd and 5th notes of the scale. So, the patterns of intervals to form a major or minor chord from any note are:
To make sure you understand, a G major chord would consist of G-B-D. A G minor chord would consist of G-A#/Bb-D. Key Notation When referring to major keys the letter of the tonic note is used, for example A major is "A". Minor keys are followed with an 'm', for example A minor is "Am". There is also a system of key codes based off the circle of fifths which assists in harmonic mixing. Sometimes songs have a key but are shifted from the standard pitch defined for notes (especially when recorded from vinyl). For example, the A note just below middle C is defined as 440hz. However, if the song has been pitched up, these same A notes might be 450hz. These songs fall in between the standard keys, and are notated by their shift in cents from the closest key. A shift of 100 cents is equivalent to a half-step. For example, "Bm+50" is half way between Bm and Cm, and is the same as "Cm-50". The built-in MIDI keyboard can be used to determine the exact shift. Harmonic Mixing A song will be harmonically compatible if it is in:
- major - W+W, H+W
- minor - W+H, W+W
For example, a song in Cm is compatible other songs in Cm, its relative major D#/Eb, its subdominant Fm and its dominant Gm. Subdominant and dominant keys are easy to find because they are the 4th and 5th scale notes from the tonic note. Relative majors are 3 half-steps above the tonic note of the minor key (in this case, C to D#/Eb). Conversely, relative minors are 3 half-steps below the major's tonic note. A system of key codes was developed by Camelot Sound which makes this easier to remember. It assigns a code to each major and minor key based on the circle of fifths. From the chart below, you will see Cm is 5A. When working with key codes, compatible keys will always be +/- 1 number, or with the same number and a different letter. For example, 5A is compatible with 4A/6A and 5B, which corresponds to Fm/Gm and D#/Eb.
- the same key (tonic)
- a relative major/minor key
- a subdominant key (perfect 4th)
- a dominant key (perfect 5th)
When matching songs harmonically, you must be aware that changing the speed of a song also changes its key, unless a key or pitch lock feature is used. To be exact, a 5.94631% shift in speed will shift the key by a half-step. So if you're mixing a song in Cm at +6%, it's going to be in C#m/Ebm. Similarly, a change in RPM on your turntable from 33 to 45 will shift the key up 5 half-steps, from Cm to Fm. Finding a Song's Key You will first need access to a keyboard or instrument of some type. Rapid Evolution includes a built in MIDI keyboard which does the job quite well, and is useful for beginners because it displays the note/chord you are playing. You don't to be a skilled keyboard player to do this. It might be difficult to determine keys at first, but with sufficient practice it becomes easy (like beat matching). There are several strategies for finding a song's key:
Once you have found the key, the tonic, subdominant and dominant notes and chords should all sound good with the song. The tonic note in particular will blend in the most, almost disappearing into the sound picture, and your ear will eventually learn to recognize it. It sounds "at home" or centered and tends to resonate with the tones of the song. Finally, you should be able to play along with notes in the key and sound as if the original artist had put them there... For more information and software to help you with harmonic mixing, visit Mixshare.com, host of the world's largest database of song key information! You can also download the free DJ tool Rapid Evolution which includes automatic key detection and a built in MIDI keyboard to help key your songs. It also acts as a personal database for your song and mix information. Once you add key information it can tell you which songs are harmonically compatible. Enjoy!
- Play one note at a time (you might want to experiment in different octave ranges). The note that blends in the most, practically disappearing into the song, is most likely the tonic note. When you suspect a tonic note, play the subdominant and dominant notes as well. They should also sound good with the song. Once you are certain of the tonic note, to determine whether it's a major or minor key play a major and minor chord based off the tonic note and see which sounds better. You can play the notes of the major and minor scales based off the suspected tonic to be absolutely certain. Example: you suspect D to be the tonic note, so you play G and A which also sound good (you might also check to see if G or A is the tonic). Then, to determine if it's minor or major you play a D minor chord (D-F-A) and a D major chord (D-F#/Gb-A) and find the minor chord sounds better. At this point the key appears to be D minor (Dm).
- Play major or minor chords until you find the chord that blends most with the song. The subdominant and dominant chords of the same type should also sound good. It helps to stick to either major or minor chords, then to test whether the key is major or minor last. For example, find the best minor chord where its subdominant and dominant minor chords also sound good. Then, to determine if it's really minor or its relative major, play the tonic notes of each key and compare. If you are still uncertain, you can compare chords. Example: you play all 12 minor chords and find Bm to blend in the best. You test the subdominant and dominant chords, Em and F#m/Gbm, and they also sound good. Then, you compare the tonic note B with its relative major's tonic note, D, and find B blends in best. The key appears to be B minor (Bm).
- A time consuming but accurate approach is to play notes of various keys (scales) until you find the key for which the least notes clash with the song. Then, to determine if the key is major or minor, compare the tonic notes or chords of each type. Example: after playing along with the song on the keyboard, you find that all the white notes tend to sound the best, suggesting the key is either A minor or C major. You find it hard to compare the tonic notes A and C, but a C major chord sounds better than A minor. The key here seems to be C major (C)