Modifying the mood of a song through relative major/minor key changes is one of the easiest and most straightforward methods available to you – and doesn’t even need to sound “key change-y”.
All it takes to adjust a scale is switching the note you start from; all other notes will remain unchanged.
Major Scale
Major scale is one of the foundations of music theory. Once you can play one, chords can then be built from all its notes – providing a good start towards learning triad and mode chords later on in lessons.
Begin by finding the tonic (also called key) note of any major scale you choose, then work your way up and down, step by step until you discover its pattern of whole and half steps. Here are some common patterns found within major scales that you should practice until they become part of your memory bank.
Note that each string’s patterns vary slightly to accommodate for tuning differences, yet still follow a similar general structure. On the sixth string, for example, you may need to move it up one fret in order to hit C as its seventh note; but this is just an insignificant detail.
Minor Scale
Minor scales are an integral component of musical language, serving as the cornerstone for tonality and melody/harmony relationships in any piece. There are three primary minor scales; natural, harmonic and melodic. Each variant serves a different purpose within music composition and performance.
Minor-type scales offer greater flexibility. For instance, minor-type thirds can be flattened out or “lowered,” to produce major thirds for greater tonal variety in chords or scales. That small adjustment can make a huge difference to overall tonality of chords or scales.
Every major key has an associated minor scale that shares its notes but begins three half steps below its tonic, starting three half steps below it and sharing key signatures that ignore sharps and flats in their order. There are two types of minor scales; natural minor and harmonic minor share identical intervals except harmonic minor raises its seventh scale degree by half step to create an leading tone while melodic minor has both 6th and 7th sharpened for smooth ascent to tonic key.
Triads
A triad is a three-note chord consisting of a root, third and fifth note. When learning these chords it can be useful to envision them like snowpersons: root at the bottom, third in its middle and fifth on top. Each triad also possesses its own interval content and quality (major, minor, diminished or augmented) that correspond with scale degrees.
Quality in triad chords depends on the interval between their third and fifth tones; major triads sound “happy”, minor triads are “sad”, diminished triads have an “eerie” sound while augmented triads produce “fantasy” tones.
Triads can be identified using chord symbols, which display their root letter name and indicate its quality or pitch class (major, minor, diminished or augment). Sometimes this information is also presented using Roman numerals (for instance if an 11th chord were represented by roman numeral “i”). Furthermore, chords may also be described based on interval content – for instance “first inversion triads” and “second inversion triads” are two ways of referring to root position triads
Cadence
Major and minor key systems utilize four relative diatonic chord positions which relate strongly between themselves, making understanding relative scales of major and minor keys an integral component. By understanding this connection, cadences can be used to alter the mood of songs or progressions while providing closure for phrases or sections of speech.
Full cadences involve movement from a dominant area chord to the tonic (V-I). There are various kinds of cadences; authentic (or perfect authentic), half, plagal and deceptive are among them.
Remembering these relationships requires keeping each chord/scale’s different tonal centers in mind. For example, C major and B minor are related because both begin on specific notes of the same scale, yet building progressions with C major as their tonic would sound very different than one with Am as its starting point.