Brilliant. Yes, I know composers learned from teachers - this is fairly obvious, unless you're a monkey sitting in a tree. I didn't think they were just randomly sitting an a piano and then poof all of a sudden composing symphonies.
My inquiry was more along the lines of what methods were used to teach them... Once they knew the basics, how did they then excel? Particularly the earlier composers - Bach, etc. For instance, did Mozart play Bach as his repertoire pieces? Who did Bach play then? I'm sure there were many lesser known composers who they studied, but I was just curious to see if anyone had anything interesting to bring up.