Borrowed chord

[1] The mixing of the major and minor modes developed in the Baroque period.

"[1] In the minor mode, a common borrowed chord from the parallel major key is the Picardy third.

In the major mode, the most common examples of borrowed chords are those involving the ♭, also known as the lowered sixth scale degree.

[9] Chord progressions may be constructed with borrowed chords, including two progressions common in rock music, I–♭VII–♭VI–♭VII, common everywhere, and I–♭VI–IV (Playⓘ), used by bands like Genesis, Yes, and Nirvana.

[11] In popular music, the major triads on the lowered third (♭III), sixth (♭VI) and seventh (♭VII) scale degrees are common.