When guitarists (or musicians for that matter) talk about keys. For example they say that they are in the key of A. Does it mean it could be either A major or A minor or both?
Another example: Some guitarist teaches the E minor pentatonic scale to some beginner. It's a continuation of learning the 12 bar blues in the key of E. So he's going to learn the scale that he can use to start improvising guitar solos in that same key.
Here he uses the words: "same key". He learned E major first, then he's going to learn E minor, but the teacher say that its the same key.
Would this mean that the key of E can contain notes from both E and Em? But its a bit confusing because I heard that with the Circle of fifths the same notes in E major are D-Flat minor, A Major has same notes as F#-minor and so on. How does these things relate to eachother when talking about keys? I think I need some extra push to understand what musicians mean when they talk about keys. Thank you.