Courtesy of Principal Horn Julie Landsman, here's the Metropolitan Opera's 2006 "Assistant Principal/General Horn Audition Repertoire."
1. Bellini, V. - I Puritani: No. 8 Duetto e Finale 2 (m.8 to 13th of A)- Horn 1
2. Beethoven, L. - Fidelio: Overture (Beginning to reh. D) - Horn 2
3a.Berg, A. - Wozzeck: Act 1, sc. 2 (m.274 to 278)- Horn 4
3b.Berg, A. - Wozzeck: Act 1, sc. 4 (m.713-736) - Horn 4
4. Berg, A. - Lulu: Act 1, sc. 2 (m.989-992) - Horn 3
5. Puccini, G. - Tosca: Act 3 (opening) - Horn 4
6. Wagner, R. - Das Rheingold: (Prelude) - Horn 2
7. Strauss, R. - Der Rosenkavalier: Act 3 (reh. 252+1 - 254) - Horn 3
8. Strauss, R. - Ariadne auf Naxos: Opera (reh. 33-40+4) - Horn 1
9. Verdi, G. - Falstaff: Act 1, Part 2 (reh. 26-27+8) - Horn 3
10.Verdi, G. - Don Carlo: Act 2, No. 1 (Beginning to reh. A+5) - Horn 1
11.Wagner, R. - Lohengrin: Act 3 (Introduction) - Horn 3
12.Wagner, R. - Siegfried: Act 3 (End of Act) - Horn 3
13.Wagner, R. - Die Meistersinger: Act 2 (Pillow Fight at the end of Act) - Hn. 1
14.Wagner, R. - Götterdämmerung: Act 2, sc. 2 - Horn 2
15.Rossini, G. - Il Barbiere di Siviglia: Overture - Horn 1
Bill Scharnberg, Principal Horn in the Dallas Opera (and also Editor of
The Horn Call) provided this:
As to the Dallas Opera orchestra rep list, I would expect we would include (depending on high/low): Das Rheingold opening, solo from Salome's Dance, Barber of Seville Overture (or one of the other solos in Rossini operas), Lohengrin Prelude to the 3rd Act, Siegfried Call (short), Tosca opening to the 3rd act, opening to Rosenkavalier, and not much more.