Generic titles should not be italicized or put in quotations:
Beethoven's Symphony No. 7 in A Major, op. 92
Piano Concerto in A Minor by Robert Schumann
Mozart, Requiem, K. 626
Note that in titles the pitch and the tonality are capitalized.
Opus numbers appear last, without capitalization, and are preceded by a comma.
The abbreviation for any cataloguer (Köchel = K.) is given as a capital letter.
If a work such as those listed above also has a title, the title is listed at the end, in italics, preceded by a comma:
Mahler’s Symphony No. 2 in C Minor, Resurrection
Symphony No. 5 in D Major, op. 107, Reformation by Mendelssohn
In a paper, the first appearance of a title should appear in full, as in the examples above. Subsequent references to the same work can be in shortened form, such as:
The Resurrection Symphony by Mahler
Beethoven’s Seventh Symphony
Non-generic titles should be italicized, including song titles that are not a part of a larger work or cycle. Here are several examples:
Bartók, Concerto for Orchestra
Brahms, Variations on a Theme by Joseph Haydn, op. 56a
Ravel, Alborada del gracioso
R. Strauss, Also sprach Zarathustra
A hierarchy of italics (opera title) and quotations should be used for aria titles:
Wagner, "Ein Schwert verhiess mir der Vater" from Die Walküre
Verdi, "Sempre libera" from La Traviata
"Ein Schwert verhiess mir der Vater" from Wagner’s Die Walküre
"Sempre libera" from La Traviata by Verdi
Note that the title of the opera is in italics, and the title of the excerpt, recitative or aria is in quotes. This system can also be applied to any work where individual sections have titles separate from that of the complete work, including oratorios and song cycles:
Schubert, "Der Lindenbaum" from Winterreisse
Strauss, "Klänge der Heimat" from act II of Fledermaus
For recitatives and arias or sections of a scene, give both titles (first few words) connected by three dots between the texts.