Some stuff that seems obvious gets asked rarely enough that a lot of folks don't take a look at it. One example is the muted lick that comes after the Waltz in
Petrushka (#151-158). Sections from Strauss' Tone Poems that arent' the "big" licks are also often overlooked, as are a lot of Wagner's works. For these examples, I guess it just comes down to learning the whole piece when it's on a list, you know?
As far as actual rarities go: I remember St. Louis' list for the 2nd trumpet audition had some stuff you don't often see on auditions. Prokofiev's
Cinderella, Webern
Six Pieces (original version) and
Passacaglia, John Harbison's
Concerto for Double Brass Choir, and Barber's
Symphony no. 1. On Seattle's Principal list from a few years ago, there was Schoenberg's
Chamber Symphony no. 2. Also, San Francisco had Mahler 8 and Schoenberg's
Theme and Variations, op. 43a on their principal list. I didn't go to either of those auditions, so I don't know if those pieces were ultimately asked or not. For the National Symphony audition last year, they indicated the audition would be mostly "sight reading from the standard repertoire". I was lucky enough to make it to the finals, and the only thing asked all day that you wouldn't expect to see on a "normal" list was Copland 3. There was some section playing from Shostakovich 5, Mahler 1 and 2, and the Beethoven
Violin Concerto - but those are probably pieces most trumpet players are quite familiar with.
As a sign of things to come, I'll relay a story I heard that a recent London Symphony violin audition included excerpts from
Harry Potter (which has a gnarly violin part)! God knows John Williams has written a lot of stuff that would be "audition-worthy" for trumpets.
