A natural minor scale is a seven note' diatonic scale with a numeric formula of 1-2-♭3-4-5-♭6-♭7-8/1 and is the sixth of seven modes of the major scale and is given the name of Aeolian. Another way to think of a natural minor scale is simply a major scale started on the sixth degree and finished on the sixth an octave above. This is why the term "Natural" precedes minor as it is a naturally occurring minor scale derived from major.
When reading manuscript or charts, if the composer gives no other description other than "Minor" then you can safely assume it to mean a natural minor although there are two other scales that should be considered, which are melodic minor (also known as Jazz minor) and harmonic minor.
Natural minor scale profile
|Notation formula (key of A)||A-B-C-D-E-F-G-A/1|
|Stepping||whole, half, whole, whole, half, whole, whole|
|Tonal||tone, semi-tone, tone, tone, semi-tone, tone, tone|
|Harmonized triads (key of A)||Ami / B⁰ / CMA / Dmi / Emi / FMA / GMA|
|Harmonized tetrads (key of C)||Ami7 / Bmi7(♭5) / CMA7 / Dmi7 / Emi7 / FMA7 / G7|
Natural minor scale patterns
Natural minor scale audio sample(s)
|C Natural minor scale pattern #4|