From major, flatten 3, 6, and 7; from this site's usual angle, it's what the key looks like standing on the 6-. This is the relative-minor machinery in person — same seven notes as the parent major, different front door — and the parallel-minor borrowing that powers half the lessons here (b3, b6, b7, 4-) is major reaching into exactly this drawer. Its signature walk is 1- → b7 → b6: three shrugging steps down, no leading tone, no urgency, just weather. Where harmonic minor sharpens the 7 to build a proper 5⁷, Aeolian keeps it flat and stays fatalistic.
The b6 — the darkest note minor keeps; it leans a half step down onto 5 and gives the mode its sigh.
Your tonic is the 6 of the parent — the major key a minor 3rd up shares every note. A Aeolian is C major's set with A as home: the relative minor by its Sunday name.
No leading tone means no real dominant — a 5- into 1- drifts rather than lands. When the minor key needs to CLOSE, borrow the raised 7 for one chord (the harmonic-minor moment); when it needs to brood, stay pure.
'All Along the Watchtower' loops 1- → b7 → b6 in both the Dylan and Hendrix tellings; the songbook's 'Wayfaring Stranger' lives in this weather, with a harmonic-minor sharpening at the cadences.