Need help understanding minor keys
I've been playing piano for about 6 months now and I'm starting to get into composing. To me being a good musician isn't about playing songs written by other people, rather being able to WRITE music!
So this week I did a composition in Cm but an interesting issue came up. In the minor keys, the 5th is a Major but per my teacher it's given a major quality by raising the 7th a half step....??
This is a cause of confusion for me. My understanding of Major chords is that they are constructed from the root-3rd-5th. Minor chords differ in that the 3rd is flatted. So if I'm in a minor key and the 5th is Major, why isn't the chord constructed with a 3rd of a normal major chord? Instead it's given a major quality by raising the 7th? WTH is that??
Sounds like in a minor key for the major 5th, the root-3rd-5th is the same as the normal minor chord but adding a raised 7th. Seems to blow everything I thought I knew about chord construction out of the water.
Can anyone help me out here? Or is it something I just need to push the "I believe" button for??
Dave
Guitars: Ibanez AF-75, Schecter Solo-6 Custom, Douglas SG
Amps: Fender Princeton 65, Marshall AVT50
Pedals: Metal Muff, MXR Smart Gate, EHX Cathedral Reverb, Digitech RP-255