Use letters in roman without intervening spaces or dashes to indicate the musical form of a work or movement:
ABA, ABACAB'A, ABaAabAB (note: use a straight apostrophe for the prime sign, not a curved right single quote or apostrophe)
"Major" and "Minor" are capitalized when part of a title of a musical work: Nocturne in D Minor; D-Minor Nocturne; D-Minor Violin Concerto; C-Minor Symphony. But not capitalized in the context of a pitch, key, or chord: the movement begins in D minor; the D-major triad (CMS16, 7.67).
For pitch designations, use the system
C2 C1 C c c1 c2 c3 c4, with middle C as c.
Generic pitch names are capitalized: middle C, a high D (CMS16, 7.67).
Generic pitch names use roman, not italic typeface. An exception may be made to clarify text.
The author needs to name the pitch a below middle C.
Musical symbols (♭flat, ♯sharp, and natural signs) are preferred when referring to the key or pitch of a note or movement (ex. "Mozart wrote a D♯ in the manuscript, not E♭"). Use the word for the key or pitch as the prose demands it (ex. "in this edition, there is a sharp in the key signature"), and use the word when referring to the title of a work (Beethoven's Bagatelle in B-flat Major).
Plurals: D♯s (not D♯'s), D♭s (not D♭'s)
Because musical symbols are not available in most word-processing programs, it is preferable to spell the words in the submitted manuscript, and the copy editors will code as is appropriate for the symbols to replace the words during production.
Hyphenate half-note (English system: minim), quarter-note (crotchet), eighth-note (quaver), sixteenth-note (semiquaver), thirty-second-note (demisemiquaver), sixty-fourth-note (hemidemisemiquaver)
BUT: whole note (semibreve), double whole note (breve), except when used as adjective
Use italic typeface for hexachord and modern syllable names (Irvine, p. 199):
do, re, mi, fa, sol, la, ti
Use regular (i.e., nonbold) italics for abbreviated dynamics: p, f, fff, etc.
Use roman for written-out dynamics: piano, forte, fortissimo, etc.
Notes prefers text over symbol. When this proves cumbersome, as within parentheses, use an equal sign and include spaces on both sides of it. See examples in CMS16, 10.48–49: "Apocalypse ( = Revelation)," "Song of Solomon ( = Song of Songs)."
Use time signatures (they will be typeset vertically aligned without the fraction line) when referring to the meter of a measure or section if the prose remains clear (ex. "The editor has changed the original time signature of 4/2 to 4/4.")
Spell out the time signature when the prose so demands: "This march is in six-eight time" (not "This march is in 6/8" or "This march is in 6/8 time").