I think you still might be able to get tickets for the matinee! But in case you don't, they also have evening shows on Sundays, so you'll have more of a chance at a ticket. I rushed the show a few Sundays ago, and I arrived to the box office at maybe 12:30 or so. I got a ticket for the evening show; my seat was in the second row, orchestra center. It was an amazing experience! I hope you get to enjoy the show!