INTRODUCTION TO MUSICAL PROGRESSION OTHERWISE KNOWN AS CHORD PROGRESSION

A chord progression or harmonic progression is a succession of musical chords, which are two or more notes, typically sounded simultaneously. Chord progressions are the foundation of harmony in Western musical tradition from the common practice era of Classical music to the 21st century. Chord progressions are the foundation of Western popular music styles (e.g., pop music, rock music) and traditional music (e.g., blues and jazz). In these genres, chord progressions are the defining feature on which melody and rhythm are built.

In tonal music, chord progressions have the function of establishing or contradicting a tonality, the technical name for what is commonly understood as the "key" of a song or piece. Chord progressions are usually expressed by Roman numerals in Classical music theory; for example, the common chord progression I vi/ii V7. In many styles of popular and traditional music, chord progressions are expressed using the name and "quality" of the chords. For example, the previously mentioned chord progression, in the key of C Major, would be written as C Major A minor/D minor G7 in a fake book or lead sheet. In the first chord, C Major, the "C" indicates that the chord is built on the root note "C"; the word "Major" indicates that a major chord is built on this "C" note.