Dramatic, unfettered and truly unpredictable, the Metropolitan Opera National Council Auditions dismantle nearly all of the barriers that keep people away from music’s highest art form. Expensive? Hardly. Tickets to the singing competition are $10 — and that is a “suggested” donation. Elite? Not at all. Anyone can audition. Just sign up and pay a $30 fee, which helps to cover the expense of the contest and pay the pianist who is supplied at no additional cost for the audition.