The A Ionian mode (that's the same as the A major scale, remember ... re building simple major and minor triads (three-note ...
Altered chords contain non-diatonic notes – that is, notes that have been raised or lowered from their usual place in the scale. The examples below provide further explanation! As a reference ...
Haydn’s Symphony No. 101 in D major, ‘The Clock’, is in a major key and uses mainly diatonic chords: A dominant seventh is used at the end of the phrase before the first time bar.