Minoring in 3rds?
# 1
Please be more specific. If your seen it on a website, send a link to that page so we can look at it.
"My whole life is a dark room...ONE BIG DARK ROOM" - a.f.i.
# 2
you don't "minor in" 3rds but you can run thru any scale using a sequence based on major and minor third intervals or you could paly double stops using intervals of thirds which are inversion of 6ths
# 3