Can't seem to figure out the key of a chord progression?

Question

Ab min7 - Db min - Eb min7 - Gb7 I looked it up and it said it was in the key of B and Ab min? Not very good with theory so I don't know how it could be a major and minor key at the same time. Thanks in advance.

Answer 1

Any given key signature on a piece in sheet music indicates two different keys that share that key signature. Which of the two keys applies to that piece depends on the musical context. Every major key has a relative minor key. The relative minor key is the sixth degree of the major scale. So a key signature of one sharp – F sharp – would indicate the key of G Major. The sixth degree of the G Major scale is E. So the relative minor of G Major is E Minor.

Answer 2

Every major key also has a relative minor key, they are always one and a half step apart. In this case this progression is the key of Ab Minor. It's relative major key is B Major, or if we were to be picky and use the right nomenclature, Cb Major.