If you haven’t made reservations to see Sunday’s VocalEssence concert that features choral superstar Eric Whitacre, you’re not entirely out of luck.

Choral music enthusiasts from 26 states, Canada and Japan bought out all the available seats in Orchestra Hall in Minneapolis more than a week ago. That’s about 2,500 seats.

But the hall, for the most part, would have been empty during the early-afternoon final rehearsal that precedes the 4 p.m. concert. So last week, VocalEssence announced that tickets will be sold for those who want to watch and listen to the rehearsal — at $20 each, general admission. To get tickets to the 12:20-2:20 p.m. rehearsal, go here. Whitacre, one of the most popular choral composers alive today, is expected to conduct some of the program, which includes the world premiere of “Nox Aurumque,” a work commissioned from him by VocalEssence.

Check out Whitacre's work here.

Participating in the concert are the VocalEssence Chorus and Ensemble Singers, the St. Olaf Choir and the Minnesota High School Honors Choir. Each group will perform separately and in combination with other groups, leading up to a finale involving a giant combined choir. Most of the works on the program are by Whitacre. To see the program order, go here.