How do you barre two strings? I've watched other players do it and the top joint of their finger seems to bend backwards so the top part of their finger lays flat. My fingers do not do this. I can get the two strings pressed down but then the third one below it gets muted because my finger doesn't bend far enough to clear the third string. Is this a "keep trying and eventually you'll stretch your finger out and it'll work" or is this a "sorry about your luck, genetics will never enable you to do this" ?