This is the guideline for titles or parts of titles in English. Do not assume that anything expressed here is valid for other languages.
Catalogue & number
Catalogues should always be preceded by comma and space.
Opus and number should always be lower-cased and abbreviated: op. and no. There should be a space before the number.
Specific catalogues (eg. Köchel) should follow their usual capitalization.
op. 27 no. 3
Symphony no. 5
String Quartet in D major, op. 11
The word "in" should always precede the key name. The key itself should be in upper case, except on releases where lowercase is used to express a minor key (see below).
If the key name contain the words "sharp" or "flat", they should be in lower case and a hyphen should be used as delimiter.
The words "major" & "minor" are always lower-cased. Do not add "major" or "minor" if these words are omitted in the source; tonality is sometimes expressed with capitalization (upper case = major, lower case = minor), or omission (naked key = major, "minor" printed).
- Using "major" or "minor" is the preferred style for generic Works titles in English.
Sonata in C-sharp minor
Symphony in E major
Suite no. 4 in E-flat (major omitted, but implied) - but work Suite no. 4 in E-flat major
Concerto in c (lowercase implies minor) - but work Concerto in C minor
English titles in general should follow MusicBrainz's standard capitalization for English, but librettos and quotes should always follow sentence style.
Always use double quotes in English titles.
Songs of Travel: The Roadside Fire
Songs of Travel: Bright is the ring of words
Nocturne from "A Midsummer Night's Dream"
"Träume" - "Schmerzen" from the "Wesendonck" Lieder