How do you become a director without going broke paying for a bunch of classes? Lean on the power of a “Material Girl,†of course. Speaking at this year’s Tribeca Festival on Thursday, director David Fincher said he thought of music videos and TV commercials as his film school. “I really went at it going, I don’t want to spend my own money trying all this stuff out. So let’s see if Madonna will finance it,†he joked. For reference, Fincher directed multiple Madonna music videos, including “Vogue,†“Oh Father,†and “Express Yourself.†Of course, he also helmed projects for artists such as Michael Jackson, the Rolling Stones, and Aerosmith, while his commercial credits include Nike, Coca-Cola, Chanel, and more. Still, since Fincher specifically mentioned Madonna as his informal film-school financier, it seems reasonable to conclude that his time working on her music videos was formative. Fincher eventually transitioned into directing movies like 2010’s The Social Network, which he discussed at Tribeca. “It was a pretty tight script,†Fincher recalled. “And part of getting it made was saying we’re gonna get this in under two hours, even if it’s 178 pages or whatever it is — like, we’re just gonna have everybody talk really fast.†Basically, if you think about it, Madonna is partly responsible for those speedy Jesse Eisenberg monologues.